diff --git a/lib/SaferpayJson/Request/Container/Address.php b/lib/SaferpayJson/Request/Container/Address.php
index 8db8fd8..0acddaa 100644
--- a/lib/SaferpayJson/Request/Container/Address.php
+++ b/lib/SaferpayJson/Request/Container/Address.php
@@ -14,94 +14,79 @@ final class Address
     public const GENDER_COMPANY = 'COMPANY';
 
     /**
-     * @var string|null
      * @SerializedName("FirstName")
      */
-    private $firstName;
+    private ?string $firstName = null;
 
     /**
-     * @var string|null
      * @SerializedName("LastName")
      */
-    private $lastName;
+    private ?string $lastName = null;
 
     /**
-     * @var string|null
      * @SerializedName("Company")
      */
-    private $company;
+    private ?string $company = null;
 
     /**
-     * @var string|null
      * @SerializedName("Gender")
      */
-    private $gender;
+    private ?string $gender = null;
 
     /**
-     * @var string|null
      * @SerializedName("Street")
      */
-    private $street;
+    private ?string $street = null;
 
     /**
-     * @var string|null
      * @SerializedName("Zip")
      */
-    private $zip;
+    private ?string $zip = null;
 
     /**
-     * @var string|null
      * @SerializedName("City")
      */
-    private $city;
+    private ?string $city = null;
 
     /**
-     * @var string|null
      * @SerializedName("CountryCode")
      */
-    private $countryCode;
+    private ?string $countryCode = null;
 
     /**
-     * @var string|null
      * @SerializedName("Email")
      */
-    private $email;
+    private ?string $email = null;
 
     /**
-     * @var \DateTime|null
      * @SerializedName("DateOfBirth")
      */
-    private $dateOfBirth;
+    private ?\DateTime $dateOfBirth = null;
 
     /**
-     * @var string|null
      * @SerializedName("LegalForm")
      */
-    private $legalForm;
+    private ?string $legalForm = null;
 
     /**
-     * @var string|null
      * @SerializedName("Street2")
      */
-    private $street2;
+    private ?string $street2 = null;
 
     /**
-     * @var string|null
      * @SerializedName("CountrySubdivisionCode")
      */
-    private $countrySubdivisionCode;
+    private ?string $countrySubdivisionCode = null;
 
     /**
-     * @var string|null
      * @SerializedName("Phone")
      */
-    private $phone;
+    private ?string $phone = null;
 
     /**
-     * @var string|null
      * @SerializedName("VatNumber")
      */
-    private $vatNumber;
+    private ?string $vatNumber = null;
 
     public function getFirstName(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/AddressForm.php b/lib/SaferpayJson/Request/Container/AddressForm.php
index a9a61ea..d03228e 100644
--- a/lib/SaferpayJson/Request/Container/AddressForm.php
+++ b/lib/SaferpayJson/Request/Container/AddressForm.php
@@ -25,16 +25,15 @@ final class AddressForm
     public const ADDRESS_SOURCE_PREFER_PAYMENTMETHOD = 'PREFER_PAYMENTMETHOD';
 
     /**
-     * @var string
      * @SerializedName("AddressSource")
      */
-    private $addressSource;
+    private string $addressSource;
 
     /**
      * @var array<string>|null
      * @SerializedName("MandatoryFields")
      */
-    private $mandatoryFields = [];
+    private ?array $mandatoryFields = [];
 
     public function __construct(string $addressSource)
     {
diff --git a/lib/SaferpayJson/Request/Container/Alias.php b/lib/SaferpayJson/Request/Container/Alias.php
index 08a101b..1e08273 100644
--- a/lib/SaferpayJson/Request/Container/Alias.php
+++ b/lib/SaferpayJson/Request/Container/Alias.php
@@ -9,16 +9,14 @@
 final class Alias
 {
     /**
-     * @var string
      * @SerializedName("Id")
      */
-    private $id;
+    private string $id;
 
     /**
-     * @var string|null
      * @SerializedName("VerificationCode")
      */
-    private $verificationCode;
+    private ?string $verificationCode = null;
 
     public function __construct(string $id)
     {
diff --git a/lib/SaferpayJson/Request/Container/Alipay.php b/lib/SaferpayJson/Request/Container/Alipay.php
index 3b9cf2a..d8dc840 100644
--- a/lib/SaferpayJson/Request/Container/Alipay.php
+++ b/lib/SaferpayJson/Request/Container/Alipay.php
@@ -9,10 +9,9 @@
 final class Alipay
 {
     /**
-     * @var string
      * @SerializedName("LocalWallet")
      */
-    private $localWallet;
+    private string $localWallet;
 
     public function __construct(string $localWallet)
     {
diff --git a/lib/SaferpayJson/Request/Container/Amount.php b/lib/SaferpayJson/Request/Container/Amount.php
index 203cf72..359bb75 100644
--- a/lib/SaferpayJson/Request/Container/Amount.php
+++ b/lib/SaferpayJson/Request/Container/Amount.php
@@ -10,17 +10,15 @@
 final class Amount
 {
     /**
-     * @var int
      * @SerializedName("Value")
      * @Type("integer")
      */
-    private $value;
+    private int $value;
 
     /**
-     * @var string
      * @SerializedName("CurrencyCode")
      */
-    private $currencyCode;
+    private string $currencyCode;
 
     public function __construct(int $value, string $currencyCode)
     {
diff --git a/lib/SaferpayJson/Request/Container/ApplePay.php b/lib/SaferpayJson/Request/Container/ApplePay.php
index c276a97..c7630fb 100644
--- a/lib/SaferpayJson/Request/Container/ApplePay.php
+++ b/lib/SaferpayJson/Request/Container/ApplePay.php
@@ -9,10 +9,9 @@
 final class ApplePay
 {
     /**
-     * @var string
      * @SerializedName("PaymentToken")
      */
-    private $paymentToken;
+    private string $paymentToken;
 
     public function __construct(string $paymentToken)
     {
diff --git a/lib/SaferpayJson/Request/Container/Attachment.php b/lib/SaferpayJson/Request/Container/Attachment.php
index bdd37d8..6629887 100644
--- a/lib/SaferpayJson/Request/Container/Attachment.php
+++ b/lib/SaferpayJson/Request/Container/Attachment.php
@@ -9,16 +9,14 @@
 final class Attachment
 {
     /**
-     * @var string
      * @SerializedName("ContentType")
      */
-    private $contentType;
+    private string $contentType;
 
     /**
-     * @var string
      * @SerializedName("Body")
      */
-    private $body;
+    private string $body;
 
     public function __construct(string $contentType, string $body)
     {
diff --git a/lib/SaferpayJson/Request/Container/Authentication.php b/lib/SaferpayJson/Request/Container/Authentication.php
index 7f35905..6baf269 100644
--- a/lib/SaferpayJson/Request/Container/Authentication.php
+++ b/lib/SaferpayJson/Request/Container/Authentication.php
@@ -16,16 +16,14 @@ final class Authentication
     public const THREEDSCHALLENGE_AVOID = 'AVOID';
 
     /**
-     * @var string|null
      * @SerializedName("Exemption")
      */
-    private $exemption;
+    private ?string $exemption = null;
 
     /**
-     * @var string|null
      * @SerializedName("ThreeDsChallenge")
      */
-    private $threeDsChallenge;
+    private ?string $threeDsChallenge = null;
 
     public function getExemption(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/BankAccount.php b/lib/SaferpayJson/Request/Container/BankAccount.php
index 897963f..3c4c742 100644
--- a/lib/SaferpayJson/Request/Container/BankAccount.php
+++ b/lib/SaferpayJson/Request/Container/BankAccount.php
@@ -9,28 +9,24 @@
 final class BankAccount
 {
     /**
-     * @var string
      * @SerializedName("Iban")
      */
-    private $iban;
+    private string $iban;
 
     /**
-     * @var string|null
      * @SerializedName("HolderName")
      */
-    private $holderName;
+    private ?string $holderName = null;
 
     /**
-     * @var string|null
      * @SerializedName("BIC")
      */
-    private $bic;
+    private ?string $bic = null;
 
     /**
-     * @var string|null
      * @SerializedName("BankName")
      */
-    private $bankName;
+    private ?string $bankName = null;
 
     public function __construct(string $iban)
     {
diff --git a/lib/SaferpayJson/Request/Container/Billpay.php b/lib/SaferpayJson/Request/Container/Billpay.php
index 47c5bea..96dd8ed 100644
--- a/lib/SaferpayJson/Request/Container/Billpay.php
+++ b/lib/SaferpayJson/Request/Container/Billpay.php
@@ -9,10 +9,9 @@
 final class Billpay
 {
     /**
-     * @var int|null
      * @SerializedName("DelayInDays")
      */
-    private $delayInDays;
+    private ?int $delayInDays = null;
 
     public function getDelayInDays(): ?int
     {
diff --git a/lib/SaferpayJson/Request/Container/Brand.php b/lib/SaferpayJson/Request/Container/Brand.php
index 8dce9c7..9d55d76 100644
--- a/lib/SaferpayJson/Request/Container/Brand.php
+++ b/lib/SaferpayJson/Request/Container/Brand.php
@@ -9,16 +9,14 @@
 final class Brand
 {
     /**
-     * @var string|null
      * @SerializedName("PaymentMethod")
      */
-    private $paymentMethod;
+    private ?string $paymentMethod = null;
 
     /**
-     * @var string|null
      * @SerializedName("Name")
      */
-    private $name;
+    private ?string $name = null;
 
     public function getPaymentMethod(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/CaptureReference.php b/lib/SaferpayJson/Request/Container/CaptureReference.php
index 55d16d7..a64d41c 100644
--- a/lib/SaferpayJson/Request/Container/CaptureReference.php
+++ b/lib/SaferpayJson/Request/Container/CaptureReference.php
@@ -9,28 +9,24 @@
 final class CaptureReference
 {
     /**
-     * @var string|null
      * @SerializedName("CaptureId")
      */
-    private $captureId;
+    private ?string $captureId = null;
 
     /**
-     * @var string|null
      * @SerializedName("TransactionId")
      */
-    private $transactionId;
+    private ?string $transactionId = null;
 
     /**
-     * @var string|null
      * @SerializedName("OrderId")
      */
-    private $orderId;
+    private ?string $orderId = null;
 
     /**
-     * @var string|null
      * @SerializedName("OrderPartId")
      */
-    private $orderPartId;
+    private ?string $orderPartId = null;
 
     public function getCaptureId(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/Card.php b/lib/SaferpayJson/Request/Container/Card.php
index 272d608..e542324 100644
--- a/lib/SaferpayJson/Request/Container/Card.php
+++ b/lib/SaferpayJson/Request/Container/Card.php
@@ -10,36 +10,31 @@
 final class Card
 {
     /**
-     * @var string|null
      * @SerializedName("Number")
      */
-    private $number;
+    private ?string $number = null;
 
     /**
-     * @var int|null
      * @SerializedName("ExpYear")
      * @Type("integer")
      */
-    private $expYear;
+    private ?int $expYear = null;
 
     /**
-     * @var int|null
      * @SerializedName("ExpMonth")
      * @Type("integer")
      */
-    private $expMonth;
+    private ?int $expMonth = null;
 
     /**
-     * @var string|null
      * @SerializedName("HolderName")
      */
-    private $holderName;
+    private ?string $holderName = null;
 
     /**
-     * @var string|null
      * @SerializedName("CountryCode")
      */
-    private $countryCode;
+    private ?string $countryCode = null;
 
     public function getNumber(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/CardForm.php b/lib/SaferpayJson/Request/Container/CardForm.php
index fe75081..88f71b2 100644
--- a/lib/SaferpayJson/Request/Container/CardForm.php
+++ b/lib/SaferpayJson/Request/Container/CardForm.php
@@ -12,10 +12,9 @@ final class CardForm
     public const HOLDER_NAME_MANDATORY = 'MANDATORY';
 
     /**
-     * @var string|null
      * @SerializedName("HolderName")
      */
-    private $holderName;
+    private ?string $holderName = null;
 
     public function getHolderName(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/Check.php b/lib/SaferpayJson/Request/Container/Check.php
index 58a03ed..d80279a 100644
--- a/lib/SaferpayJson/Request/Container/Check.php
+++ b/lib/SaferpayJson/Request/Container/Check.php
@@ -12,16 +12,14 @@ final class Check
     public const TYPE_ONLINE_STRONG = 'ONLINE_STRONG';
 
     /**
-     * @var string|null
      * @SerializedName("Type")
      */
-    private $type;
+    private ?string $type = null;
 
     /**
-     * @var string|null
      * @SerializedName("TerminalId")
      */
-    private $terminalId;
+    private ?string $terminalId = null;
 
     public function getType(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/ChosenPlan.php b/lib/SaferpayJson/Request/Container/ChosenPlan.php
index 0a2b8f7..330ff33 100644
--- a/lib/SaferpayJson/Request/Container/ChosenPlan.php
+++ b/lib/SaferpayJson/Request/Container/ChosenPlan.php
@@ -10,51 +10,44 @@
 final class ChosenPlan
 {
     /**
-     * @var int
      * @SerializedName("NumberOfInstallments")
      * @Type("int")
      */
-    private $numberOfInstallments;
+    private int $numberOfInstallments;
 
     /**
-     * @var string|null
      * @SerializedName("InterestRate")
      */
-    private $interestRate;
+    private ?string $interestRate = null;
 
     /**
-     * @var Amount|null
      * @SerializedName("InstallmentFee")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Amount")
      */
-    private $installmentFee;
+    private ?Amount $installmentFee = null;
 
     /**
-     * @var string|null
      * @SerializedName("AnnualPercentageRate")
      */
-    private $annualPercentageRate;
+    private ?string $annualPercentageRate = null;
 
     /**
-     * @var Amount|null
      * @SerializedName("FirstInstallmentAmount")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Amount")
      */
-    private $firstInstallmentAmount;
+    private ?Amount $firstInstallmentAmount = null;
 
     /**
-     * @var Amount|null
      * @SerializedName("SubsequentInstallmentAmount")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Amount")
      */
-    private $subsequentInstallmentAmount;
+    private ?Amount $subsequentInstallmentAmount = null;
 
     /**
-     * @var Amount|null
      * @SerializedName("TotalAmountDue")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Amount")
      */
-    private $totalAmountDue;
+    private ?Amount $totalAmountDue = null;
 
     public function __construct(int $numberOfInstallments)
     {
diff --git a/lib/SaferpayJson/Request/Container/ClientInfo.php b/lib/SaferpayJson/Request/Container/ClientInfo.php
index 247f6ce..2bfce19 100644
--- a/lib/SaferpayJson/Request/Container/ClientInfo.php
+++ b/lib/SaferpayJson/Request/Container/ClientInfo.php
@@ -9,16 +9,14 @@
 final class ClientInfo
 {
     /**
-     * @var string|null
      * @SerializedName("ShopInfo")
      */
-    private $shopInfo;
+    private ?string $shopInfo = null;
 
     /**
-     * @var string|null
      * @SerializedName("OsInfo")
      */
-    private $osInfo;
+    private ?string $osInfo = null;
 
     public function getShopInfo(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/GooglePay.php b/lib/SaferpayJson/Request/Container/GooglePay.php
index 7d23c3d..acadb66 100644
--- a/lib/SaferpayJson/Request/Container/GooglePay.php
+++ b/lib/SaferpayJson/Request/Container/GooglePay.php
@@ -9,10 +9,9 @@
 final class GooglePay
 {
     /**
-     * @var string
      * @SerializedName("PaymentToken")
      */
-    private $paymentToken;
+    private string $paymentToken;
 
     public function __construct(string $paymentToken)
     {
diff --git a/lib/SaferpayJson/Request/Container/Ideal.php b/lib/SaferpayJson/Request/Container/Ideal.php
index a246d97..cc0e305 100644
--- a/lib/SaferpayJson/Request/Container/Ideal.php
+++ b/lib/SaferpayJson/Request/Container/Ideal.php
@@ -9,10 +9,9 @@
 final class Ideal
 {
     /**
-     * @var string
      * @SerializedName("IssuerId")
      */
-    private $issuerId;
+    private string $issuerId;
 
     public function __construct(string $issuerId)
     {
diff --git a/lib/SaferpayJson/Request/Container/Installment.php b/lib/SaferpayJson/Request/Container/Installment.php
index 60a9950..ded078d 100644
--- a/lib/SaferpayJson/Request/Container/Installment.php
+++ b/lib/SaferpayJson/Request/Container/Installment.php
@@ -9,10 +9,9 @@
 final class Installment
 {
     /**
-     * @var bool
      * @SerializedName("Initial")
      */
-    private $initial;
+    private bool $initial;
 
     public function __construct(bool $initial)
     {
diff --git a/lib/SaferpayJson/Request/Container/IssuerReference.php b/lib/SaferpayJson/Request/Container/IssuerReference.php
index a239cfa..bd29fc5 100644
--- a/lib/SaferpayJson/Request/Container/IssuerReference.php
+++ b/lib/SaferpayJson/Request/Container/IssuerReference.php
@@ -10,18 +10,16 @@
 final class IssuerReference
 {
     /**
-     * @var string
      * @SerializedName("TransactionStamp")
      * @Type("string")
      */
-    private $transactionStamp;
+    private string $transactionStamp;
 
     /**
-     * @var string|null
      * @SerializedName("SettlementDate")
      * @Type("string")
      */
-    private $settlementDate;
+    private ?string $settlementDate = null;
 
     public function __construct(string $transactionStamp)
     {
diff --git a/lib/SaferpayJson/Request/Container/Klarna.php b/lib/SaferpayJson/Request/Container/Klarna.php
index 48796ce..e4bf627 100644
--- a/lib/SaferpayJson/Request/Container/Klarna.php
+++ b/lib/SaferpayJson/Request/Container/Klarna.php
@@ -10,11 +10,10 @@
 final class Klarna
 {
     /**
-     * @var Attachment
      * @SerializedName("Attachment")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Attachment")
      */
-    private $attachment;
+    private Attachment $attachment;
 
     public function __construct(Attachment $attachment)
     {
diff --git a/lib/SaferpayJson/Request/Container/Marketplace.php b/lib/SaferpayJson/Request/Container/Marketplace.php
index b3798f2..d704111 100644
--- a/lib/SaferpayJson/Request/Container/Marketplace.php
+++ b/lib/SaferpayJson/Request/Container/Marketplace.php
@@ -9,22 +9,19 @@
 final class Marketplace
 {
     /**
-     * @var string
      * @SerializedName("SubmerchantId")
      */
-    private $submerchantId;
+    private string $submerchantId;
 
     /**
-     * @var Amount|null
      * @SerializedName("Fee")
      */
-    private $fee;
+    private ?Amount $fee = null;
 
     /**
-     * @var Amount|null
      * @SerializedName("FeeRefund")
      */
-    private $feeRefund;
+    private ?Amount $feeRefund = null;
 
     public function __construct(string $submerchantId)
     {
diff --git a/lib/SaferpayJson/Request/Container/MastercardIssuerInstallments.php b/lib/SaferpayJson/Request/Container/MastercardIssuerInstallments.php
index 74adbe5..2446667 100644
--- a/lib/SaferpayJson/Request/Container/MastercardIssuerInstallments.php
+++ b/lib/SaferpayJson/Request/Container/MastercardIssuerInstallments.php
@@ -10,11 +10,10 @@
 final class MastercardIssuerInstallments
 {
     /**
-     * @var ChosenPlan|null
      * @SerializedName("ChosenPlan")
      * @Type("array")
      */
-    private $chosenPlan;
+    private ?ChosenPlan $chosenPlan = null;
 
     public function getChosenPlan(): ?ChosenPlan
     {
diff --git a/lib/SaferpayJson/Request/Container/Notification.php b/lib/SaferpayJson/Request/Container/Notification.php
index 9033b19..c1e7a50 100644
--- a/lib/SaferpayJson/Request/Container/Notification.php
+++ b/lib/SaferpayJson/Request/Container/Notification.php
@@ -12,25 +12,22 @@ final class Notification
      * @var array<string>|null
      * @SerializedName("MerchantEmails")
      */
-    private $merchantEmails = [];
+    private ?array $merchantEmails = [];
 
     /**
-     * @var string|null
      * @SerializedName("PayerEmail")
      */
-    private $payerEmail;
+    private ?string $payerEmail = null;
 
     /**
-     * @var string|null
      * @SerializedName("SuccessNotifyUrl")
      */
-    private $successNotifyUrl;
+    private ?string $successNotifyUrl = null;
 
     /**
-     * @var string|null
      * @SerializedName("FailNotifyUrl")
      */
-    private $failNotifyUrl;
+    private ?string $failNotifyUrl = null;
 
     public function getMerchantEmails(): ?array
     {
diff --git a/lib/SaferpayJson/Request/Container/Options.php b/lib/SaferpayJson/Request/Container/Options.php
index c190bf6..e348dce 100644
--- a/lib/SaferpayJson/Request/Container/Options.php
+++ b/lib/SaferpayJson/Request/Container/Options.php
@@ -9,16 +9,14 @@
 final class Options
 {
     /**
-     * @var bool|null
      * @SerializedName("PreAuth")
      */
-    private $preAuth;
+    private ?bool $preAuth = null;
 
     /**
-     * @var bool|null
      * @SerializedName("AllowPartialAuthorization")
      */
-    private $allowPartialAuthorization;
+    private ?bool $allowPartialAuthorization = null;
 
     public function isPreAuth(): ?bool
     {
diff --git a/lib/SaferpayJson/Request/Container/Order.php b/lib/SaferpayJson/Request/Container/Order.php
index b709ed8..c386938 100644
--- a/lib/SaferpayJson/Request/Container/Order.php
+++ b/lib/SaferpayJson/Request/Container/Order.php
@@ -12,7 +12,7 @@ final class Order
      * @var array<OrderItem>|null
      * @SerializedName("Items")
      */
-    private $items = [];
+    private ?array $items = [];
 
     public function getItems(): ?array
     {
diff --git a/lib/SaferpayJson/Request/Container/OrderItem.php b/lib/SaferpayJson/Request/Container/OrderItem.php
index c6d7cf4..19dfb4e 100644
--- a/lib/SaferpayJson/Request/Container/OrderItem.php
+++ b/lib/SaferpayJson/Request/Container/OrderItem.php
@@ -18,88 +18,74 @@ final class OrderItem
     public const TYPE_SURCHARGE = 'SURCHARGE';
 
     /**
-     * @var string|null
      * @SerializedName("Type")
      */
-    private $type;
+    private ?string $type = null;
 
     /**
-     * @var string|null
      * @SerializedName("Id")
      */
-    private $id;
+    private ?string $id = null;
 
     /**
-     * @var string|null
      * @SerializedName("VariantId")
      */
-    private $variantId;
+    private ?string $variantId = null;
 
     /**
-     * @var string|null
      * @SerializedName("Name")
      */
-    private $name;
+    private ?string $name = null;
 
     /**
-     * @var string|null
      * @SerializedName("CategoryName")
      */
-    private $categoryName;
+    private ?string $categoryName = null;
 
     /**
-     * @var string|null
      * @SerializedName("Description")
      */
-    private $description;
+    private ?string $description = null;
 
     /**
-     * @var string|null
      * @SerializedName("Quantity")
      */
-    private $quantity;
+    private ?string $quantity = null;
 
     /**
-     * @var string|null
      * @SerializedName("UnitPrice")
      */
-    private $unitPrice;
+    private ?string $unitPrice = null;
 
     /**
-     * @var string|null
      * @SerializedName("IsPreOrder")
      */
-    private $isPreOrder;
+    private ?string $isPreOrder = null;
 
     /**
-     * @var string|null
      * @SerializedName("TaxRate")
      */
-    private $taxRate;
+    private ?string $taxRate = null;
 
     /**
-     * @var string|null
      * @SerializedName("TaxAmount")
      */
-    private $taxAmount;
+    private ?string $taxAmount = null;
 
     /**
-     * @var string|null
      * @SerializedName("DiscountAmount")
      */
-    private $discountAmount;
+    private ?string $discountAmount = null;
 
     /**
-     * @var string|null
      * @SerializedName("ProductUrl")
      */
-    private $productUrl;
+    private ?string $productUrl = null;
 
     /**
-     * @var string|null
      * @SerializedName("ImageUrl")
      */
-    private $imageUrl;
+    private ?string $imageUrl = null;
 
 
     public function getType(): ?string
diff --git a/lib/SaferpayJson/Request/Container/Payer.php b/lib/SaferpayJson/Request/Container/Payer.php
index 5223950..1502412 100644
--- a/lib/SaferpayJson/Request/Container/Payer.php
+++ b/lib/SaferpayJson/Request/Container/Payer.php
@@ -10,35 +10,30 @@
 final class Payer
 {
     /**
-     * @var string|null
      * @SerializedName("Id")
      */
-    private $id;
+    private ?string $id = null;
 
     /**
-     * @var string|null
      * @SerializedName("IpAddress")
      */
-    private $ipAddress;
+    private ?string $ipAddress = null;
     /**
-     * @var string|null
      * @SerializedName("LanguageCode")
      */
-    private $languageCode;
+    private ?string $languageCode = null;
 
     /**
-     * @var Address|null
      * @SerializedName("DeliveryAddress")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Address")
      */
-    private $deliveryAddress;
+    private ?Address $deliveryAddress = null;
 
     /**
-     * @var Address|null
      * @SerializedName("BillingAddress")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Address")
      */
-    private $billingAddress;
+    private ?Address $billingAddress = null;
 
     public function getId(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/PayerProfile.php b/lib/SaferpayJson/Request/Container/PayerProfile.php
index 4b4c479..e076e12 100644
--- a/lib/SaferpayJson/Request/Container/PayerProfile.php
+++ b/lib/SaferpayJson/Request/Container/PayerProfile.php
@@ -15,91 +15,77 @@ final class PayerProfile
     public const GENDER_COMPANY = "COMPANY";
 
     /**
-     * @var bool|null
      * @SerializedName("HasAccount")
      */
-    private $hasAccount;
+    private ?bool $hasAccount = null;
 
     /**
-     * @var bool|null
      * @SerializedName("HasPassword")
      */
-    private $hasPassword;
+    private ?bool $hasPassword = null;
 
     /**
-     * @var bool|null
      * @SerializedName("PasswordForgotten")
      */
-    private $passwordForgotten;
+    private ?bool $passwordForgotten = null;
 
     /**
-     * @var string|null
      * @SerializedName("FirstName")
      */
-    private $firstName;
+    private ?string $firstName = null;
 
     /**
-     * @var string|null
      * @SerializedName("LastName")
      */
-    private $lastName;
+    private ?string $lastName = null;
 
     /**
-     * @var string|null
      * @SerializedName("Company")
      */
-    private $company;
+    private ?string $company = null;
 
     /**
-     * @var string|null
      * @SerializedName("DateOfBirth")
      */
-    private $dateOfBirth;
+    private ?string $dateOfBirth = null;
 
     /**
-     * @var \DateTime|null
      * @SerializedName("LastLoginDate")
      * @Type("DateTime<'Y-m-d\TH:i:s.uT'>")
      */
-    private $lastLoginDate;
+    private ?\DateTime $lastLoginDate = null;
 
     /**
-     * @var string|null
      * @SerializedName("Gender")
      */
-    private $gender;
+    private ?string $gender = null;
 
     /**
-     * @var \DateTime|null
      * @SerializedName("CreationDate")
      * @Type("DateTime<'Y-m-d\TH:i:s.uT'>")
      */
-    private $creationDate;
+    private ?\DateTime $creationDate = null;
 
     /**
-     * @var \DateTime|null
      * @SerializedName("PasswordLastChangeDate")
      * @Type("DateTime<'Y-m-d\TH:i:s.uT'>")
      */
-    private $passwordLastChangeDate;
+    private ?\DateTime $passwordLastChangeDate = null;
 
     /**
-     * @var string|null
      * @SerializedName("Email")
      */
-    private $email;
+    private ?string $email = null;
 
     /**
-     * @var string|null
      * @SerializedName("SecondaryEmail")
      */
-    private $secondaryEmail;
+    private ?string $secondaryEmail = null;
 
     /**
-     * @var Phone|null
      * @SerializedName("Phone")
      */
-    private $phone;
+    private ?Phone $phone = null;
 
     public function getHasAccount(): ?bool
     {
diff --git a/lib/SaferpayJson/Request/Container/Payment.php b/lib/SaferpayJson/Request/Container/Payment.php
index 8842d03..a73d603 100644
--- a/lib/SaferpayJson/Request/Container/Payment.php
+++ b/lib/SaferpayJson/Request/Container/Payment.php
@@ -9,52 +9,44 @@
 final class Payment
 {
     /**
-     * @var Amount
      * @SerializedName("Amount")
      */
-    private $amount;
+    private Amount $amount;
 
     /**
-     * @var string|null
      * @SerializedName("OrderId")
      */
-    private $orderId;
+    private ?string $orderId = null;
 
     /**
-     * @var string|null
      * @SerializedName("PayerNote")
      */
-    private $payerNote;
+    private ?string $payerNote = null;
 
     /**
-     * @var string|null
      * @SerializedName("Description")
      */
-    private $description;
+    private ?string $description = null;
 
     /**
-     * @var string|null
      * @SerializedName("MandateId")
      */
-    private $mandateId;
+    private ?string $mandateId = null;
 
     /**
-     * @var Options|null
      * @SerializedName("Options")
      */
-    private $options;
+    private ?Options $options = null;
 
     /**
-     * @var Recurring|null
      * @SerializedName("Recurring")
      */
-    private $recurring;
+    private ?Recurring $recurring = null;
 
     /**
-     * @var Installment|null
      * @SerializedName("Installment")
      */
-    private $installment;
+    private ?Installment $installment = null;
 
     public function __construct(Amount $amount)
     {
diff --git a/lib/SaferpayJson/Request/Container/PaymentMeans.php b/lib/SaferpayJson/Request/Container/PaymentMeans.php
index 0236177..2800711 100644
--- a/lib/SaferpayJson/Request/Container/PaymentMeans.php
+++ b/lib/SaferpayJson/Request/Container/PaymentMeans.php
@@ -10,79 +10,68 @@
 final class PaymentMeans
 {
     /**
-     * @var Brand|null
      * @SerializedName("Brand")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Brand")
      */
-    private $brand;
+    private ?Brand $brand = null;
 
     /**
-     * @var string|null
      * @SerializedName("DisplayText")
      */
-    private $displayText;
+    private ?string $displayText = null;
 
     /**
-     * @var string|null
      * @SerializedName("Wallet")
      */
-    private $wallet;
+    private ?string $wallet = null;
 
     /**
-     * @var Card|null
      * @SerializedName("Card")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Card")
      */
-    private $card;
+    private ?Card $card = null;
 
     /**
-     * @var BankAccount|null
      * @SerializedName("BankAccount")
      * @Type("Ticketpark\SaferpayJson\Request\Container\BankAccount")
      */
-    private $bankAccount;
+    private ?BankAccount $bankAccount = null;
 
     /**
-     * @var Twint|null
      * @SerializedName("Twint")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Twint")
      */
-    private $twint;
+    private ?Twint $twint = null;
 
     /**
-     * @var SaferpayFields|null
      * @SerializedName("SaferpayFields")
      * @Type("Ticketpark\SaferpayJson\Request\Container\SaferpayFields")
      */
-    private $saferpayFields;
+    private ?SaferpayFields $saferpayFields = null;
 
     /**
-     * @var Alias|null
      * @SerializedName("Alias")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Alias")
      */
-    private $alias;
+    private ?Alias $alias = null;
 
     /**
-     * @var SchemeToken|null
      * @SerializedName("SchemeToken")
      * @Type("Ticketpark\SaferpayJson\Request\Container\SchemeToken")
      */
-    private $schemeToken;
+    private ?SchemeToken $schemeToken = null;
 
     /**
-     * @var ApplePay|null
      * @SerializedName("ApplePay")
      * @Type("Ticketpark\SaferpayJson\Request\Container\ApplePay")
      */
-    private $applePay;
+    private ?ApplePay $applePay = null;
 
     /**
-     * @var GooglePay|null
      * @SerializedName("GooglePay")
      * @Type("Ticketpark\SaferpayJson\Request\Container\GooglePay")
      */
-    private $googlePay;
+    private ?GooglePay $googlePay = null;
 
     public function getBrand(): ?Brand
     {
diff --git a/lib/SaferpayJson/Request/Container/PaymentMethodsOptions.php b/lib/SaferpayJson/Request/Container/PaymentMethodsOptions.php
index 026c0ea..4829e3f 100644
--- a/lib/SaferpayJson/Request/Container/PaymentMethodsOptions.php
+++ b/lib/SaferpayJson/Request/Container/PaymentMethodsOptions.php
@@ -10,25 +10,22 @@
 final class PaymentMethodsOptions
 {
     /**
-     * @var Alipay|null
      * @SerializedName("Alipay")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Alipay")
      */
-    private $alipay;
+    private ?Alipay $alipay = null;
 
     /**
-     * @var Ideal|null
      * @SerializedName("Ideal")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Ideal")
      */
-    private $ideal;
+    private ?Ideal $ideal = null;
 
     /**
-     * @var Klarna|null
      * @SerializedName("Klarna")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Klarna")
      */
-    private $klarna;
+    private ?Klarna $klarna = null;
 
     public function getAlipay(): ?Alipay
     {
diff --git a/lib/SaferpayJson/Request/Container/PendingNotification.php b/lib/SaferpayJson/Request/Container/PendingNotification.php
index 204954f..254048b 100644
--- a/lib/SaferpayJson/Request/Container/PendingNotification.php
+++ b/lib/SaferpayJson/Request/Container/PendingNotification.php
@@ -12,13 +12,12 @@ final class PendingNotification
      * @var array<string>|null
      * @SerializedName("MerchantEmails")
      */
-    private $merchantEmails = [];
+    private ?array $merchantEmails = [];
 
     /**
-     * @var string|null
      * @SerializedName("NotifyUrl")
      */
-    private $notifyUrl;
+    private ?string $notifyUrl = null;
 
     public function getMerchantEmails(): ?array
     {
diff --git a/lib/SaferpayJson/Request/Container/Phone.php b/lib/SaferpayJson/Request/Container/Phone.php
index 2ad0847..97a4acd 100644
--- a/lib/SaferpayJson/Request/Container/Phone.php
+++ b/lib/SaferpayJson/Request/Container/Phone.php
@@ -9,22 +9,19 @@
 final class Phone
 {
     /**
-     * @var string|null
      * @SerializedName("Main")
      */
-    private $main;
+    private ?string $main = null;
 
     /**
-     * @var string|null
      * @SerializedName("Mobile")
      */
-    private $mobile;
+    private ?string $mobile = null;
 
     /**
-     * @var string|null
      * @SerializedName("Work")
      */
-    private $work;
+    private ?string $work = null;
 
     public function getMain(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/Recurring.php b/lib/SaferpayJson/Request/Container/Recurring.php
index 7b522e2..da2e8cc 100644
--- a/lib/SaferpayJson/Request/Container/Recurring.php
+++ b/lib/SaferpayJson/Request/Container/Recurring.php
@@ -9,10 +9,9 @@
 final class Recurring
 {
     /**
-     * @var bool
      * @SerializedName("Initial")
      */
-    private $initial;
+    private bool $initial;
 
     public function __construct(bool $initial = true)
     {
diff --git a/lib/SaferpayJson/Request/Container/RedirectNotifyUrls.php b/lib/SaferpayJson/Request/Container/RedirectNotifyUrls.php
index fac3ba2..1893353 100644
--- a/lib/SaferpayJson/Request/Container/RedirectNotifyUrls.php
+++ b/lib/SaferpayJson/Request/Container/RedirectNotifyUrls.php
@@ -9,16 +9,14 @@
 final class RedirectNotifyUrls
 {
     /**
-     * @var string
      * @SerializedName("Success")
      */
-    private $success;
+    private string $success;
 
     /**
-     * @var string
      * @SerializedName("Fail")
      */
-    private $fail;
+    private string $fail;
 
     public function __construct(string $success, string $fail)
     {
diff --git a/lib/SaferpayJson/Request/Container/Refund.php b/lib/SaferpayJson/Request/Container/Refund.php
index d92bb18..08df477 100644
--- a/lib/SaferpayJson/Request/Container/Refund.php
+++ b/lib/SaferpayJson/Request/Container/Refund.php
@@ -10,29 +10,25 @@
 final class Refund
 {
     /**
-     * @var Amount|null
      * @SerializedName("Amount")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Amount")
      */
-    private $amount;
+    private ?Amount $amount = null;
 
     /**
-     * @var string|null
      * @SerializedName("OrderId")
      */
-    private $orderId;
+    private ?string $orderId = null;
 
     /**
-     * @var string|null
      * @SerializedName("Description")
      */
-    private $description;
+    private ?string $description = null;
 
     /**
-     * @var bool|null
      * @SerializedName("RestrictRefundAmountToCapturedAmount")
      */
-    private $restrictRefundAmountToCapturedAmount;
+    private ?bool $restrictRefundAmountToCapturedAmount = null;
 
     public function __construct(?Amount $amount)
     {
diff --git a/lib/SaferpayJson/Request/Container/RegisterAlias.php b/lib/SaferpayJson/Request/Container/RegisterAlias.php
index cc56d95..76e29f4 100644
--- a/lib/SaferpayJson/Request/Container/RegisterAlias.php
+++ b/lib/SaferpayJson/Request/Container/RegisterAlias.php
@@ -14,23 +14,20 @@ final class RegisterAlias
     public const ID_GENERATOR_RANDOM_UNIQUE = 'RANDOM_UNIQUE';
 
     /**
-     * @var string
      * @SerializedName("IdGenerator")
      */
-    private $idGenerator;
+    private string $idGenerator;
 
     /**
-     * @var string|null
      * @SerializedName("Id")
      */
-    private $id;
+    private ?string $id = null;
 
     /**
-     * @var int|null
      * @SerializedName("Lifetime")
      * @Type("integer")
      */
-    private $lifetime;
+    private ?int $lifetime = null;
 
     public function __construct(string $idGenerator)
     {
diff --git a/lib/SaferpayJson/Request/Container/RequestHeader.php b/lib/SaferpayJson/Request/Container/RequestHeader.php
index 16c4a5e..ec40baf 100644
--- a/lib/SaferpayJson/Request/Container/RequestHeader.php
+++ b/lib/SaferpayJson/Request/Container/RequestHeader.php
@@ -9,34 +9,29 @@
 final class RequestHeader
 {
     /**
-     * @var string
      * @SerializedName("SpecVersion")
      */
-    private $specVersion = '1.31';
+    private string $specVersion = '1.31';
 
     /**
-     * @var string
      * @SerializedName("CustomerId")
      */
-    private $customerId;
+    private string $customerId;
 
     /**
-     * @var string|null
      * @SerializedName("RequestId")
      */
-    private $requestId;
+    private ?string $requestId = null;
 
     /**
-     * @var int
      * @SerializedName("RetryIndicator")
      */
-    private $retryIndicator = 0;
+    private int $retryIndicator = 0;
 
     /**
-     * @var ClientInfo|null
      * @SerializedName("ClientInfo")
      */
-    private $clientInfo;
+    private ?ClientInfo $clientInfo = null;
 
     public function __construct(string $customerId, string $requestId = null, int $retryIndicator = 0)
     {
diff --git a/lib/SaferpayJson/Request/Container/ReturnUrls.php b/lib/SaferpayJson/Request/Container/ReturnUrls.php
index ab8a511..0abd559 100644
--- a/lib/SaferpayJson/Request/Container/ReturnUrls.php
+++ b/lib/SaferpayJson/Request/Container/ReturnUrls.php
@@ -9,22 +9,19 @@
 final class ReturnUrls
 {
     /**
-     * @var string
      * @SerializedName("Success")
      */
-    private $success;
+    private string $success;
 
     /**
-     * @var string
      * @SerializedName("Fail")
      */
-    private $fail;
+    private string $fail;
 
     /**
-     * @var string|null
      * @SerializedName("Abort")
      */
-    private $abort;
+    private ?string $abort = null;
 
     public function __construct(string $success, string $fail, string $abort = null)
     {
diff --git a/lib/SaferpayJson/Request/Container/RiskFactors.php b/lib/SaferpayJson/Request/Container/RiskFactors.php
index e338bcb..9c2376d 100644
--- a/lib/SaferpayJson/Request/Container/RiskFactors.php
+++ b/lib/SaferpayJson/Request/Container/RiskFactors.php
@@ -16,29 +16,25 @@ final class RiskFactors
     public const DELIVERY_TYPE_HQ = "HQ";
 
     /**
-     * @var string|null
      * @SerializedName("DeliveryType")
      */
-    private $deliveryType;
+    private ?string $deliveryType = null;
 
     /**
-     * @var PayerProfile|null
      * @SerializedName("PayerProfile")
      * @Type("Ticketpark\SaferpayJson\Request\Container\PayerProfile")
      */
-    private $payerProfile;
+    private ?PayerProfile $payerProfile = null;
 
     /**
-     * @var bool|null
      * @SerializedName("IsB2B")
      */
-    private $isB2B;
+    private ?bool $isB2B = null;
 
     /**
-     * @var string|null
      * @SerializedName("DeviceFingerprint")
      */
-    private $deviceFingerprint;
+    private ?string $deviceFingerprint = null;
 
     public function getDeliveryType(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/SaferpayFields.php b/lib/SaferpayJson/Request/Container/SaferpayFields.php
index 4162213..ae7be43 100644
--- a/lib/SaferpayJson/Request/Container/SaferpayFields.php
+++ b/lib/SaferpayJson/Request/Container/SaferpayFields.php
@@ -9,10 +9,9 @@
 final class SaferpayFields
 {
     /**
-     * @var string
      * @SerializedName("Token")
      */
-    private $token;
+    private string $token;
 
     public function __construct(string $token)
     {
diff --git a/lib/SaferpayJson/Request/Container/SchemeToken.php b/lib/SaferpayJson/Request/Container/SchemeToken.php
index 1b958f5..5443e45 100644
--- a/lib/SaferpayJson/Request/Container/SchemeToken.php
+++ b/lib/SaferpayJson/Request/Container/SchemeToken.php
@@ -10,38 +10,33 @@
 final class SchemeToken
 {
     /**
-     * @var string
      * @SerializedName("Number")
      * @Type("string")
      */
-    private $number;
+    private string $number;
 
     /**
-     * @var int
      * @SerializedName("ExpMonth")
      * @Type("integer")
      */
-    private $expMonth;
+    private int $expMonth;
 
     /**
-     * @var int
      * @SerializedName("ExpYear")
      * @Type("integer")
      */
-    private $expYear;
+    private int $expYear;
 
     /**
-     * @var string
      * @SerializedName("AuthValue")
      * @Type("string")
      */
-    private $authValue;
+    private string $authValue;
 
     /**
-     * @var string|null
      * @SerializedName("Eci")
      */
-    private $eci;
+    private ?string $eci = null;
 
     public function __construct(string $number, int $expMonth, int $expYear, string $authValue)
     {
diff --git a/lib/SaferpayJson/Request/Container/Styling.php b/lib/SaferpayJson/Request/Container/Styling.php
index fd4b9e2..4b71e93 100644
--- a/lib/SaferpayJson/Request/Container/Styling.php
+++ b/lib/SaferpayJson/Request/Container/Styling.php
@@ -13,22 +13,19 @@ final class Styling
     public const THEME_NONE = 'NONE';
 
     /**
-     * @var string|null
      * @SerializedName("CssUrl")
      */
-    private $cssUrl;
+    private ?string $cssUrl = null;
 
     /**
-     * @var bool|null
      * @SerializedName("ContentSecurityEnabled")
      */
-    private $contentSecurityEnabled;
+    private ?bool $contentSecurityEnabled = null;
 
     /**
-     * @var string|null
      * @SerializedName("Theme")
      */
-    private $theme;
+    private ?string $theme = null;
 
     public function getCssUrl(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/TransactionReference.php b/lib/SaferpayJson/Request/Container/TransactionReference.php
index feab0bb..3811a81 100644
--- a/lib/SaferpayJson/Request/Container/TransactionReference.php
+++ b/lib/SaferpayJson/Request/Container/TransactionReference.php
@@ -9,16 +9,14 @@
 final class TransactionReference
 {
     /**
-     * @var string|null
      * @SerializedName("TransactionId")
      */
-    private $transactionId;
+    private ?string $transactionId = null;
 
     /**
-     * @var string|null
      * @SerializedName("OrderId")
      */
-    private $orderId;
+    private ?string $orderId = null;
 
     public function getTransactionId(): ?string
     {
diff --git a/lib/SaferpayJson/Request/Container/Twint.php b/lib/SaferpayJson/Request/Container/Twint.php
index 4a517e0..af00bba 100644
--- a/lib/SaferpayJson/Request/Container/Twint.php
+++ b/lib/SaferpayJson/Request/Container/Twint.php
@@ -10,11 +10,10 @@
 final class Twint
 {
     /**
-     * @var \DateTime|null
      * @SerializedName("CertificateExpirationDate")
      * @Type("DateTime<'Y-m-d\TH:i:s.uT'>")
      */
-    private $certificateExpirationDate;
+    private ?\DateTime $certificateExpirationDate = null;
 
     public function getCertificateExpirationDate(): ?\DateTime
     {
diff --git a/lib/SaferpayJson/Request/Container/UpdateAlias.php b/lib/SaferpayJson/Request/Container/UpdateAlias.php
index 9e3bc61..c2e7c4d 100644
--- a/lib/SaferpayJson/Request/Container/UpdateAlias.php
+++ b/lib/SaferpayJson/Request/Container/UpdateAlias.php
@@ -10,17 +10,15 @@
 final class UpdateAlias
 {
     /**
-     * @var string
      * @SerializedName("Id")
      */
-    private $id;
+    private string $id;
 
     /**
-     * @var int|null
      * @SerializedName("Lifetime")
      * @Type("integer")
      */
-    private $lifetime;
+    private ?int $lifetime = null;
 
     public function __construct(string $id)
     {
diff --git a/lib/SaferpayJson/Request/Container/UpdatePaymentMeans.php b/lib/SaferpayJson/Request/Container/UpdatePaymentMeans.php
index 85d19b8..34cd717 100644
--- a/lib/SaferpayJson/Request/Container/UpdatePaymentMeans.php
+++ b/lib/SaferpayJson/Request/Container/UpdatePaymentMeans.php
@@ -9,10 +9,9 @@
 final class UpdatePaymentMeans
 {
     /**
-     * @var Card
      * @SerializedName("Card")
      */
-    private $card;
+    private Card $card;
 
     public function __construct(Card $card)
     {
diff --git a/lib/SaferpayJson/Request/Container/Wallet.php b/lib/SaferpayJson/Request/Container/Wallet.php
index 8dbf40d..16ffc88 100644
--- a/lib/SaferpayJson/Request/Container/Wallet.php
+++ b/lib/SaferpayJson/Request/Container/Wallet.php
@@ -34,28 +34,25 @@ final class Wallet
     public const PAYMENT_METHOD_KLARNA = "KLARNA";
 
     /**
-     * @var string
      * @SerializedName("Wallet")
      */
-    private $type;
+    private string $type;
 
     /**
      * @var array<string>|null
      * @SerializedName("PaymentMethods")
      */
-    private $paymentMethods;
+    private ?array $paymentMethods = null;
 
     /**
-     * @var bool|null
      * @SerializedName("RequestDeliveryAddress")
      */
-    private $requestDeliveryAddress;
+    private ?bool $requestDeliveryAddress = null;
 
     /**
-     * @var bool|null
      * @SerializedName("EnableAmountAdjustment")
      */
-    private $enableAmountAdjustment;
+    private ?bool $enableAmountAdjustment = null;
 
     public function __construct(string $type)
     {
diff --git a/lib/SaferpayJson/Request/Exception/SaferpayErrorException.php b/lib/SaferpayJson/Request/Exception/SaferpayErrorException.php
index 7d99a68..4472ebb 100644
--- a/lib/SaferpayJson/Request/Exception/SaferpayErrorException.php
+++ b/lib/SaferpayJson/Request/Exception/SaferpayErrorException.php
@@ -8,8 +8,7 @@
 
 class SaferpayErrorException extends \Exception
 {
-    /** @var ErrorResponse */
-    private $errorResponse;
+    private ErrorResponse $errorResponse;
 
     public function __construct(ErrorResponse $errorResponse)
     {
diff --git a/lib/SaferpayJson/Request/PaymentPage/AssertRequest.php b/lib/SaferpayJson/Request/PaymentPage/AssertRequest.php
index 7d03efd..f9554a7 100644
--- a/lib/SaferpayJson/Request/PaymentPage/AssertRequest.php
+++ b/lib/SaferpayJson/Request/PaymentPage/AssertRequest.php
@@ -17,10 +17,9 @@ final class AssertRequest extends Request
     public const RESPONSE_CLASS = AssertResponse::class;
 
     /**
-     * @var string
      * @SerializedName("Token")
      */
-    private $token;
+    private string $token;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/PaymentPage/InitializeRequest.php b/lib/SaferpayJson/Request/PaymentPage/InitializeRequest.php
index 2857f3e..7ec573d 100644
--- a/lib/SaferpayJson/Request/PaymentPage/InitializeRequest.php
+++ b/lib/SaferpayJson/Request/PaymentPage/InitializeRequest.php
@@ -62,112 +62,96 @@ final class InitializeRequest extends Request
     public const CONDITION_IF_ALLOWED_BY_SCHEME = 'IF_ALLOWED_BY_SCHEME';
 
     /**
-     * @var string
      * @SerializedName("TerminalId")
      */
-    private $terminalId;
+    private string $terminalId;
 
     /**
-     * @var Payment
      * @SerializedName("Payment")
      */
-    private $payment;
+    private Payment $payment;
 
     /**
-     * @var ReturnUrls
      * @SerializedName("ReturnUrls")
      */
-    private $returnUrls;
+    private ReturnUrls $returnUrls;
 
     /**
-     * @var string|null
      * @SerializedName("ConfigSet")
      */
-    private $configSet;
+    private ?string $configSet = null;
 
     /**
      * @var array<string>|null
      * @SerializedName("PaymentMethods")
      */
-    private $paymentMethods;
+    private ?array $paymentMethods = null;
 
     /**
-     * @var PaymentMethodsOptions|null
      * @SerializedName("PaymentMethodsOptions")
      */
-    private $paymentMethodsOptions;
+    private ?PaymentMethodsOptions $paymentMethodsOptions = null;
 
     /**
-     * @var Authentication|null
      * @SerializedName("Authentication")
      */
-    private $authentication;
+    private ?Authentication $authentication = null;
 
     /**
      * @var array<string>|null
      * @SerializedName("Wallets")
      */
-    private $wallets;
+    private ?array $wallets = null;
 
     /**
-     * @var Payer|null
      * @SerializedName("Payer")
      */
-    private $payer;
+    private ?Payer $payer = null;
 
     /**
-     * @var RegisterAlias|null
      * @SerializedName("RegisterAlias")
      */
-    private $registerAlias;
+    private ?RegisterAlias $registerAlias = null;
 
     /**
-     * @var Notification|null
      * @SerializedName("Notification")
      */
-    private $notification;
+    private ?Notification $notification = null;
 
     /**
-     * @var Styling|null
      * @SerializedName("Styling")
      */
-    private $styling;
+    private ?Styling $styling = null;
 
     /**
-     * @var AddressForm|null
      * @SerializedName("BillingAddressForm")
      */
-    private $billingAddressForm;
+    private ?AddressForm $billingAddressForm = null;
 
     /**
-     * @var AddressForm|null
      * @SerializedName("DeliveryAddressForm")
      */
-    private $deliveryAddressForm;
+    private ?AddressForm $deliveryAddressForm = null;
 
     /**
-     * @var CardForm|null
      * @SerializedName("CardForm")
      */
-    private $cardForm;
+    private ?CardForm $cardForm = null;
 
     /**
-     * @var string|null
      * @SerializedName("Condition")
      */
-    private $condition;
+    private ?string $condition = null;
 
     /**
-     * @var Order|null
      * @SerializedName("Order")
      */
-    private $order;
+    private ?Order $order = null;
 
     /**
-     * @var RiskFactors|null
      * @SerializedName("RiskFactors")
      */
-    private $riskFactors;
+    private ?RiskFactors $riskFactors = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Request.php b/lib/SaferpayJson/Request/Request.php
index eef5180..d336945 100644
--- a/lib/SaferpayJson/Request/Request.php
+++ b/lib/SaferpayJson/Request/Request.php
@@ -25,10 +25,9 @@ abstract class Request
     private const ERROR_RESPONSE_CLASS = ErrorResponse::class;
 
     /**
-     * @var RequestConfig
      * @Exclude
      */
-    private $requestConfig;
+    private RequestConfig $requestConfig;
 
     abstract public function execute(): Response;
 
diff --git a/lib/SaferpayJson/Request/RequestConfig.php b/lib/SaferpayJson/Request/RequestConfig.php
index f05e950..e482ee5 100644
--- a/lib/SaferpayJson/Request/RequestConfig.php
+++ b/lib/SaferpayJson/Request/RequestConfig.php
@@ -8,30 +8,11 @@
 
 final class RequestConfig
 {
-    /**
-     * @var string
-     */
-    private $apiKey;
-
-    /**
-     * @var string
-     */
-    private $apiSecret;
-
-    /**
-     * @var string
-     */
-    private $customerId;
-
-    /**
-     * @var bool
-     */
-    private $test;
-
-    /**
-     * @var Client
-     */
-    private $client;
+    private string $apiKey;
+    private string $apiSecret;
+    private string $customerId;
+    private bool $test;
+    private ?Client $client = null;
 
     public function __construct(string $apiKey, string $apiSecret, string $customerId, bool $test = false)
     {
diff --git a/lib/SaferpayJson/Request/SecureCardData/AliasAssertInsertRequest.php b/lib/SaferpayJson/Request/SecureCardData/AliasAssertInsertRequest.php
index eb5e2c2..44dc945 100755
--- a/lib/SaferpayJson/Request/SecureCardData/AliasAssertInsertRequest.php
+++ b/lib/SaferpayJson/Request/SecureCardData/AliasAssertInsertRequest.php
@@ -17,10 +17,9 @@ final class AliasAssertInsertRequest extends Request
     public const RESPONSE_CLASS = AliasAssertInsertResponse::class;
 
     /**
-     * @var string
      * @SerializedName("Token")
      */
-    private $token;
+    private string $token;
 
     public function __construct(RequestConfig $requestConfig, string $token)
     {
diff --git a/lib/SaferpayJson/Request/SecureCardData/AliasDeleteRequest.php b/lib/SaferpayJson/Request/SecureCardData/AliasDeleteRequest.php
index 85182c8..743b8e3 100755
--- a/lib/SaferpayJson/Request/SecureCardData/AliasDeleteRequest.php
+++ b/lib/SaferpayJson/Request/SecureCardData/AliasDeleteRequest.php
@@ -17,10 +17,9 @@ final class AliasDeleteRequest extends Request
     public const RESPONSE_CLASS = AliasDeleteResponse::class;
 
     /**
-     * @var string
      * @SerializedName("AliasId")
      */
-    private $aliasId;
+    private string $aliasId;
 
     public function __construct(RequestConfig $requestConfig, string $aliasId)
     {
diff --git a/lib/SaferpayJson/Request/SecureCardData/AliasInsertDirectRequest.php b/lib/SaferpayJson/Request/SecureCardData/AliasInsertDirectRequest.php
index 70f03fd..cd4a7f4 100755
--- a/lib/SaferpayJson/Request/SecureCardData/AliasInsertDirectRequest.php
+++ b/lib/SaferpayJson/Request/SecureCardData/AliasInsertDirectRequest.php
@@ -22,31 +22,27 @@ final class AliasInsertDirectRequest extends Request
     public const RESPONSE_CLASS = AliasInsertDirectResponse::class;
 
     /**
-     * @var RegisterAlias
      * @SerializedName("RegisterAlias")
      */
-    private $registerAlias;
+    private RegisterAlias $registerAlias;
 
     /**
-     * @var PaymentMeans
      * @SerializedName("PaymentMeans")
      * @Type("Ticketpark\SaferpayJson\Request\Container\PaymentMeans")
      */
-    private $paymentMeans;
+    private PaymentMeans $paymentMeans;
 
     /**
-     * @var Check|null
      * @SerializedName("Check")
      * @Type("Ticketpark\SaferpayJson\Request\Container\Check")
      */
-    private $check;
+    private ?Check $check = null;
 
     /**
-     * @var IssuerReference|null
      * @SerializedName("IssuerReference")
      * @Type("Ticketpark\SaferpayJson\Request\Container\IssuerReference")
      */
-    private $issuerReference;
+    private ?IssuerReference $issuerReference = null;
 
     public function __construct(RequestConfig $requestConfig, RegisterAlias $registerAlias, PaymentMeans $paymentMeans)
     {
diff --git a/lib/SaferpayJson/Request/SecureCardData/AliasInsertRequest.php b/lib/SaferpayJson/Request/SecureCardData/AliasInsertRequest.php
index 59355b4..92f504c 100755
--- a/lib/SaferpayJson/Request/SecureCardData/AliasInsertRequest.php
+++ b/lib/SaferpayJson/Request/SecureCardData/AliasInsertRequest.php
@@ -43,60 +43,52 @@ final class AliasInsertRequest extends Request
     public const TYPE_TWINT = 'TWINT';
 
     /**
-     * @var RegisterAlias
      * @SerializedName("RegisterAlias")
      */
-    private $registerAlias;
+    private RegisterAlias $registerAlias;
 
     /**
-     * @var string
      * @SerializedName("Type")
      * @Type("string")
      */
-    private $type;
+    private string $type;
 
     /**
-     * @var ReturnUrls
      * @SerializedName("ReturnUrls")
      */
-    private $returnUrls;
+    private ReturnUrls $returnUrls;
 
     /**
-     * @var Styling|null
      * @SerializedName("Styling")
      */
-    private $styling;
+    private ?Styling $styling = null;
 
     /**
-     * @var string|null
      * @SerializedName("LanguageCode")
      * @Type("string")
      */
-    private $languageCode;
+    private ?string $languageCode = null;
 
     /**
-     * @var Check|null
      * @SerializedName("Check")
      */
-    private $check;
+    private ?Check $check = null;
 
     /**
      * @var array<string>|null
      * @SerializedName("PaymentMethods")
      */
-    private $paymentMethods;
+    private ?array $paymentMethods = null;
 
     /**
-     * @var CardForm|null
      * @SerializedName("CardForm")
      */
-    private $cardForm;
+    private ?CardForm $cardForm = null;
 
     /**
-     * @var PaymentMeans|null
      * @SerializedName("PaymentMeans")
      */
-    private $paymentMeans;
+    private ?PaymentMeans $paymentMeans = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/SecureCardData/AliasUpdateRequest.php b/lib/SaferpayJson/Request/SecureCardData/AliasUpdateRequest.php
index ba98fb9..6092815 100755
--- a/lib/SaferpayJson/Request/SecureCardData/AliasUpdateRequest.php
+++ b/lib/SaferpayJson/Request/SecureCardData/AliasUpdateRequest.php
@@ -19,16 +19,14 @@ final class AliasUpdateRequest extends Request
     public const RESPONSE_CLASS = AliasUpdateResponse::class;
 
     /**
-     * @var UpdateAlias
      * @SerializedName("UpdateAlias")
      */
-    private $updateAlias;
+    private UpdateAlias $updateAlias;
 
     /**
-     * @var UpdatePaymentMeans
      * @SerializedName("UpdatePaymentMeans")
      */
-    private $updatePaymentMeans;
+    private UpdatePaymentMeans $updatePaymentMeans;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/AuthorizeDirectRequest.php b/lib/SaferpayJson/Request/Transaction/AuthorizeDirectRequest.php
index 2de064a..ca1c648 100644
--- a/lib/SaferpayJson/Request/Transaction/AuthorizeDirectRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/AuthorizeDirectRequest.php
@@ -27,58 +27,49 @@ final class AuthorizeDirectRequest extends Request
     public const INITIATOR_PAYER = 'PAYER';
 
     /**
-     * @var string
      * @SerializedName("TerminalId")
      */
-    private $terminalId;
+    private string $terminalId;
 
     /**
-     * @var Payment
      * @SerializedName("Payment")
      */
-    private $payment;
+    private Payment $payment;
 
     /**
-     * @var PaymentMeans
      * @SerializedName("PaymentMeans")
      */
-    private $paymentMeans;
+    private PaymentMeans $paymentMeans;
 
     /**
-     * @var Authentication|null
      * @SerializedName("Authentication")
      */
-    private $authentication;
+    private ?Authentication $authentication = null;
 
     /**
-     * @var RegisterAlias|null
      * @SerializedName("RegisterAlias")
      */
-    private $registerAlias;
+    private ?RegisterAlias $registerAlias = null;
 
     /**
-     * @var Payer|null
      * @SerializedName("Payer")
      */
-    private $payer;
+    private ?Payer $payer = null;
 
     /**
-     * @var Order|null
      * @SerializedName("Order")
      */
-    private $order;
+    private ?Order $order = null;
 
     /**
-     * @var RiskFactors|null
      * @SerializedName("RiskFactors")
      */
-    private $riskFactors;
+    private ?RiskFactors $riskFactors = null;
 
     /**
-     * @var string|null
      * @SerializedName("Initiator")
      */
-    private $initiator;
+    private ?string $initiator = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/AuthorizeReferencedRequest.php b/lib/SaferpayJson/Request/Transaction/AuthorizeReferencedRequest.php
index 1ada576..c51423d 100644
--- a/lib/SaferpayJson/Request/Transaction/AuthorizeReferencedRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/AuthorizeReferencedRequest.php
@@ -20,34 +20,29 @@ final class AuthorizeReferencedRequest extends Request
     public const RESPONSE_CLASS = AuthorizeReferencedResponse::class;
 
     /**
-     * @var string
      * @SerializedName("TerminalId")
      */
-    private $terminalId;
+    private string $terminalId;
 
     /**
-     * @var Payment
      * @SerializedName("Payment")
      */
-    private $payment;
+    private Payment $payment;
 
     /**
-     * @var TransactionReference
      * @SerializedName("TransactionReference")
      */
-    private $transactionReference;
+    private TransactionReference $transactionReference;
 
     /**
-     * @var Authentication|null
      * @SerializedName("Authentication")
      */
-    private $authentication;
+    private ?Authentication $authentication = null;
 
     /**
-     * @var bool|null
      * @SerializedName("SuppressDcc")
      */
-    private $suppressDcc;
+    private ?bool $suppressDcc = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/AuthorizeRequest.php b/lib/SaferpayJson/Request/Transaction/AuthorizeRequest.php
index 617dddd..8b0993d 100644
--- a/lib/SaferpayJson/Request/Transaction/AuthorizeRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/AuthorizeRequest.php
@@ -18,28 +18,24 @@ final class AuthorizeRequest extends Request
     public const RESPONSE_CLASS = AuthorizeResponse::class;
 
     /**
-     * @var string
      * @SerializedName("Token")
      */
-    private $token;
+    private string $token;
 
     /**
-     * @var string|null
      * @SerializedName("Condition")
      */
-    private $condition;
+    private ?string $condition = null;
 
     /**
-     * @var string|null
      * @SerializedName("VerificationCode")
      */
-    private $verificationCode;
+    private ?string $verificationCode = null;
 
     /**
-     * @var RegisterAlias|null
      * @SerializedName("RegisterAlias")
      */
-    private $registerAlias;
+    private ?RegisterAlias $registerAlias = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/CancelRequest.php b/lib/SaferpayJson/Request/Transaction/CancelRequest.php
index 8248689..aca2f09 100644
--- a/lib/SaferpayJson/Request/Transaction/CancelRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/CancelRequest.php
@@ -18,10 +18,9 @@ final class CancelRequest extends Request
     public const RESPONSE_CLASS = CancelResponse::class;
 
     /**
-     * @var TransactionReference
      * @SerializedName("TransactionReference")
      */
-    private $transactionReference;
+    private TransactionReference $transactionReference;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/CaptureRequest.php b/lib/SaferpayJson/Request/Transaction/CaptureRequest.php
index fc04a97..66c05d7 100644
--- a/lib/SaferpayJson/Request/Transaction/CaptureRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/CaptureRequest.php
@@ -23,40 +23,34 @@ final class CaptureRequest extends Request
     public const RESPONSE_CLASS = CaptureResponse::class;
 
     /**
-     * @var TransactionReference
      * @SerializedName("TransactionReference")
      */
-    private $transactionReference;
+    private TransactionReference $transactionReference;
 
     /**
-     * @var Amount|null
      * @SerializedName("Amount")
      */
-    private $amount;
+    private ?Amount $amount = null;
 
     /**
-     * @var Billpay|null
      * @SerializedName("Billpay")
      */
-    private $billpay;
+    private ?Billpay $billpay = null;
 
     /**
-     * @var PendingNotification|null
      * @SerializedName("PendingNotification")
      */
-    private $pendingNotification;
+    private ?PendingNotification $pendingNotification = null;
 
     /**
-     * @var Marketplace|null
      * @SerializedName("Marketplace")
      */
-    private $marketplace;
+    private ?Marketplace $marketplace = null;
 
     /**
-     * @var MastercardIssuerInstallments|null
      * @SerializedName("MastercardIssuerInstallments")
      */
-    private $mastercardIssuerInstallments;
+    private ?MastercardIssuerInstallments $mastercardIssuerInstallments = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/InitializeRequest.php b/lib/SaferpayJson/Request/Transaction/InitializeRequest.php
index 3948777..c536a54 100644
--- a/lib/SaferpayJson/Request/Transaction/InitializeRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/InitializeRequest.php
@@ -43,88 +43,75 @@ final class InitializeRequest extends Request
     public const WALLET_MASTERPASS = "MASTERPASS";
 
     /**
-     * @var string|null
      * @SerializedName("ConfigSet")
      */
-    private $configSet;
+    private ?string $configSet = null;
 
     /**
-     * @var string
      * @SerializedName("TerminalId")
      */
-    private $terminalId;
+    private string $terminalId;
 
     /**
-     * @var Payment
      * @SerializedName("Payment")
      */
-    private $payment;
+    private Payment $payment;
 
     /**
-     * @var PaymentMeans|null
      * @SerializedName("PaymentMeans")
      */
-    private $paymentMeans;
+    private ?PaymentMeans $paymentMeans = null;
 
     /**
-     * @var Authentication|null
      * @SerializedName("Authentication")
      */
-    private $authentication;
+    private ?Authentication $authentication = null;
 
     /**
-     * @var Payer|null
      * @SerializedName("Payer")
      */
-    private $payer;
+    private ?Payer $payer = null;
 
     /**
-     * @var ReturnUrls
      * @SerializedName("ReturnUrls")
      */
-    private $returnUrls;
+    private ReturnUrls $returnUrls;
 
     /**
-     * @var Styling|null
      * @SerializedName("Styling")
      */
-    private $styling;
+    private ?Styling $styling = null;
 
     /**
-     * @var Wallet|null
      * @SerializedName("Wallet")
      */
-    private $wallet;
+    private ?Wallet $wallet = null;
 
     /**
      * @var array<string>|null
      * @SerializedName("PaymentMethods")
      */
-    private $paymentMethods;
+    private ?array $paymentMethods = null;
 
     /**
-     * @var Order|null
      * @SerializedName("Order")
      */
-    private $order;
+    private ?Order $order = null;
 
     /**
-     * @var RiskFactors|null
      * @SerializedName("RiskFactors")
      */
-    private $riskFactors;
+    private ?RiskFactors $riskFactors = null;
 
     /**
-     * @var CardForm|null
      * @SerializedName("CardForm")
      */
-    private $cardForm;
+    private ?CardForm $cardForm = null;
 
     /**
-     * @var RedirectNotifyUrls|null
      * @SerializedName("RedirectNotifyUrls")
      */
-    private $redirectNotifyUrls;
+    private ?RedirectNotifyUrls $redirectNotifyUrls = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Request/Transaction/RefundRequest.php b/lib/SaferpayJson/Request/Transaction/RefundRequest.php
index 6957c86..041fe27 100644
--- a/lib/SaferpayJson/Request/Transaction/RefundRequest.php
+++ b/lib/SaferpayJson/Request/Transaction/RefundRequest.php
@@ -20,22 +20,19 @@ final class RefundRequest extends Request
     public const RESPONSE_CLASS = RefundResponse::class;
 
     /**
-     * @var Refund
      * @SerializedName("Refund")
      */
-    private $refund;
+    private Refund $refund;
 
     /**
-     * @var CaptureReference
      * @SerializedName("CaptureReference")
      */
-    private $captureReference;
+    private CaptureReference $captureReference;
 
     /**
-     * @var PendingNotification|null
      * @SerializedName("PendingNotification")
      */
-    private $pendingNotification;
+    private ?PendingNotification $pendingNotification = null;
 
     public function __construct(
         RequestConfig $requestConfig,
diff --git a/lib/SaferpayJson/Response/ErrorResponse.php b/lib/SaferpayJson/Response/ErrorResponse.php
index 92ed407..6eb3c82 100644
--- a/lib/SaferpayJson/Response/ErrorResponse.php
+++ b/lib/SaferpayJson/Response/ErrorResponse.php
@@ -51,11 +51,10 @@ class ErrorResponse extends Response
     private $transactionId;
 
     /**
-     * @var array|null
      * @SerializedName("ErrorDetail")
      * @Type("array")
      */
-    private $errorDetail = [];
+    private array $errorDetail = [];
 
     /**
      * @var string|null
diff --git a/rector.php b/rector.php
index 9fa3cf5..96668a9 100644
--- a/rector.php
+++ b/rector.php
@@ -4,6 +4,7 @@
 
 use Rector\Config\RectorConfig;
 use Rector\TypeDeclaration\Rector\ClassMethod\AddVoidReturnTypeWhereNoReturnRector;
+use Rector\TypeDeclaration\Rector\Property\TypedPropertyFromAssignsRector;
 
 return RectorConfig::configure()
     ->withPaths([
@@ -15,4 +16,5 @@
     ->withImportNames(importShortClasses: false, removeUnusedImports: true)
     ->withRules([
         AddVoidReturnTypeWhereNoReturnRector::class,
+        TypedPropertyFromAssignsRector::class
     ]);
diff --git a/tests/SaferpayJson/Tests/Request/CommonRequestTest.php b/tests/SaferpayJson/Tests/Request/CommonRequestTest.php
index dac4734..1937577 100644
--- a/tests/SaferpayJson/Tests/Request/CommonRequestTest.php
+++ b/tests/SaferpayJson/Tests/Request/CommonRequestTest.php
@@ -16,11 +16,9 @@
 
 abstract class CommonRequestTest extends TestCase
 {
-    /** @var bool */
-    private $successful;
+    private ?bool $successful = null;
 
-    /** @var ?string */
-    private $successfulResponseClass;
+    private ?string $successfulResponseClass = null;
 
     abstract protected function getInstance();