diff --git a/packages/passport/sdk/src/guardian/index.test.ts b/packages/passport/sdk/src/guardian/index.test.ts
index f0aecd1168..9b73058fed 100644
--- a/packages/passport/sdk/src/guardian/index.test.ts
+++ b/packages/passport/sdk/src/guardian/index.test.ts
@@ -164,13 +164,11 @@ describe('Guardian', () => {
               revertOnError: true,
               to: mockUserZkEvm.zkEvm.ethAddress,
               value: '0x00',
-              nonce: 5,
             },
             {
               revertOnError: true,
               to: '0x123',
               value: '0x',
-              nonce: 5,
             },
           ],
         }),
@@ -200,7 +198,6 @@ describe('Guardian', () => {
             revertOnError: true,
             to: mockUserZkEvm.zkEvm.ethAddress,
             value: '0x00',
-            nonce: 5,
           },
         ],
       });
@@ -250,7 +247,6 @@ describe('Guardian', () => {
             revertOnError: true,
             to: mockUserZkEvm.zkEvm.ethAddress,
             value: '0x00',
-            nonce: 5,
           },
         ],
         isBackgroundTransaction: true,
@@ -302,7 +298,6 @@ describe('Guardian', () => {
             revertOnError: true,
             to: mockUserZkEvm.zkEvm.ethAddress,
             value: '0x00',
-            nonce: 1,
           },
         ],
         isBackgroundTransaction: false,
@@ -354,7 +349,6 @@ describe('Guardian', () => {
             revertOnError: true,
             to: mockUserZkEvm.zkEvm.ethAddress,
             value: '0x00',
-            nonce: 1,
           },
         ],
       });
@@ -415,7 +409,6 @@ describe('Guardian', () => {
               revertOnError: true,
               to: mockUserZkEvm.zkEvm.ethAddress,
               value: '0x00',
-              nonce: 5,
             },
           ],
         });
@@ -450,13 +443,11 @@ describe('Guardian', () => {
                 revertOnError: true,
                 to: mockUserZkEvm.zkEvm.ethAddress,
                 value: '0x00',
-                nonce: 5,
               },
               {
                 revertOnError: true,
                 to: '0x123',
                 value: '0x00',
-                nonce: 5,
               },
             ],
           }),
diff --git a/packages/passport/sdk/src/guardian/index.ts b/packages/passport/sdk/src/guardian/index.ts
index d5fc6cebdf..2dbc07c5f5 100644
--- a/packages/passport/sdk/src/guardian/index.ts
+++ b/packages/passport/sdk/src/guardian/index.ts
@@ -41,7 +41,7 @@ type GuardianERC191MessageEvaluationParams = {
 const transactionRejectedCrossSdkBridgeError = 'Transaction requires confirmation but this functionality is not'
   + ' supported in this environment. Please contact Immutable support if you need to enable this feature.';
 
-export const convertBigNumberishToString = (
+const convertBigNumberishToString = (
   value: BigNumberish,
 ): string => BigInt(value).toString();
 
diff --git a/packages/passport/sdk/src/zkEvm/transactionHelpers.test.ts b/packages/passport/sdk/src/zkEvm/transactionHelpers.test.ts
index eb657c08df..85b5d5e21d 100644
--- a/packages/passport/sdk/src/zkEvm/transactionHelpers.test.ts
+++ b/packages/passport/sdk/src/zkEvm/transactionHelpers.test.ts
@@ -77,7 +77,6 @@ describe('transactionHelpers', () => {
       {
         to: transactionRequest.to,
         data: transactionRequest.data,
-        nonce,
         value: transactionRequest.value,
         revertOnError: true,
       },
@@ -171,7 +170,6 @@ describe('transactionHelpers', () => {
               revertOnError: true,
               to: transactionRequest.to,
               value: '0x00',
-              nonce: expect.any(BigInt),
             }),
           ]),
         }),
@@ -206,13 +204,11 @@ describe('transactionHelpers', () => {
               revertOnError: true,
               to: transactionRequest.to,
               value: '0x00',
-              nonce: expect.any(BigInt),
             }),
             expect.objectContaining({
               to: '0x7331',
               value: expect.any(BigInt),
               revertOnError: true,
-              nonce: expect.any(BigInt),
             }),
           ]),
         }),
@@ -225,17 +221,15 @@ describe('transactionHelpers', () => {
             revertOnError: true,
             to: transactionRequest.to,
             value: '0x00',
-            nonce: expect.any(BigInt),
           }),
           expect.objectContaining({
             to: '0x7331',
             value: expect.any(BigInt),
             revertOnError: true,
-            nonce: expect.any(BigInt),
           }),
         ]),
-        expect.any(BigInt),
-        expect.any(BigInt),
+        nonce,
+        chainId,
         zkEvmAddress,
         ethSigner,
       );
diff --git a/packages/passport/sdk/src/zkEvm/transactionHelpers.ts b/packages/passport/sdk/src/zkEvm/transactionHelpers.ts
index d607da569a..fa02ff8308 100644
--- a/packages/passport/sdk/src/zkEvm/transactionHelpers.ts
+++ b/packages/passport/sdk/src/zkEvm/transactionHelpers.ts
@@ -1,7 +1,6 @@
 import { Flow } from '@imtbl/metrics';
 import {
   Signer, TransactionRequest, JsonRpcProvider,
-  BigNumberish,
 } from 'ethers';
 import {
   getEip155ChainId,
@@ -11,7 +10,7 @@ import {
   getNonce,
 } from './walletHelpers';
 import { RelayerClient } from './relayerClient';
-import GuardianClient, { convertBigNumberishToString } from '../guardian';
+import GuardianClient from '../guardian';
 import {
   FeeOption,
   MetaTransaction,
@@ -71,11 +70,10 @@ const getFeeOption = async (
  */
 const buildMetaTransactions = async (
   transactionRequest: TransactionRequest,
-  rpcProvider: JsonRpcProvider,
   relayerClient: RelayerClient,
   zkevmAddress: string,
-  nonceSpace?: bigint,
-): Promise<[MetaTransaction, ...MetaTransaction[]]> => {
+  flow: Flow,
+): Promise<MetaTransaction[]> => {
   if (!transactionRequest.to) {
     throw new JsonRpcError(
       RpcErrorCode.INVALID_PARAMS,
@@ -83,39 +81,27 @@ const buildMetaTransactions = async (
     );
   }
 
-  const metaTransaction: MetaTransaction = {
+  const metaTransactions: MetaTransaction[] = [{
     to: transactionRequest.to.toString(),
     data: transactionRequest.data,
-    nonce: BigInt(0), // NOTE: We don't need a valid nonce to estimate the fee
     value: transactionRequest.value,
     revertOnError: true,
-  };
+  }];
 
   // Estimate the fee and get the nonce from the smart wallet
-  const [nonce, feeOption] = await Promise.all([
-    getNonce(rpcProvider, zkevmAddress, nonceSpace),
-    getFeeOption(metaTransaction, zkevmAddress, relayerClient),
-  ]);
-
-  // Build the meta transactions array with a valid nonce and fee transaction
-  const metaTransactions: [MetaTransaction, ...MetaTransaction[]] = [
-    {
-      ...metaTransaction,
-      nonce,
-    },
-  ];
+  const feeOption = await getFeeOption(metaTransactions[0], zkevmAddress, relayerClient);
 
   // Add a fee transaction if the fee is non-zero
   const feeValue = BigInt(feeOption.tokenPrice);
   if (feeValue !== BigInt(0)) {
     metaTransactions.push({
-      nonce,
       to: feeOption.recipientAddress,
       value: feeValue,
       revertOnError: true,
     });
   }
 
+  flow.addEvent('endBuildMetaTransactions');
   return metaTransactions;
 };
 
@@ -162,6 +148,12 @@ export const pollRelayerTransaction = async (
   return relayerTransaction;
 };
 
+const detectNetwork = async (rpcProvider: JsonRpcProvider, flow: Flow) => {
+  const network = await rpcProvider.getNetwork();
+  flow.addEvent('endDetectNetwork');
+  return network;
+};
+
 export const prepareAndSignTransaction = async ({
   transactionRequest,
   ethSigner,
@@ -173,30 +165,23 @@ export const prepareAndSignTransaction = async ({
   nonceSpace,
   isBackgroundTransaction,
 }: TransactionParams & { transactionRequest: TransactionRequest }) => {
-  const { chainId } = await rpcProvider.getNetwork();
-  const chainIdBigNumber = BigInt(chainId);
-  flow.addEvent('endDetectNetwork');
-
-  const metaTransactions = await buildMetaTransactions(
-    transactionRequest,
-    rpcProvider,
-    relayerClient,
-    zkEvmAddress,
-    nonceSpace,
-  );
-  flow.addEvent('endBuildMetaTransactions');
-
-  const { nonce } = metaTransactions[0];
-  if (typeof nonce === 'undefined') {
-    throw new Error('Failed to retrieve nonce from the smart wallet');
-  }
+  const [metaTransactions, nonce, network] = await Promise.all([
+    buildMetaTransactions(
+      transactionRequest,
+      relayerClient,
+      zkEvmAddress,
+      flow,
+    ),
+    getNonce(rpcProvider, zkEvmAddress, nonceSpace),
+    detectNetwork(rpcProvider, flow),
+  ]);
 
   // Parallelize the validation and signing of the transaction
   // without waiting for the validation to complete
   const validateTransaction = async () => {
     await guardianClient.validateEVMTransaction({
-      chainId: getEip155ChainId(Number(chainId)),
-      nonce: convertBigNumberishToString(nonce),
+      chainId: getEip155ChainId(Number(network.chainId)),
+      nonce: nonce.toString(),
       metaTransactions,
       isBackgroundTransaction,
     });
@@ -209,7 +194,7 @@ export const prepareAndSignTransaction = async ({
     const signed = await signMetaTransactions(
       metaTransactions,
       nonce,
-      chainIdBigNumber,
+      network.chainId,
       zkEvmAddress,
       ethSigner,
     );
@@ -230,7 +215,7 @@ export const prepareAndSignTransaction = async ({
 
 const buildMetaTransactionForEjection = async (
   transactionRequest: TransactionRequest,
-): Promise<[MetaTransaction, ...MetaTransaction[]]> => {
+): Promise<MetaTransaction> => {
   if (!transactionRequest.to) {
     throw new JsonRpcError(
       RpcErrorCode.INVALID_PARAMS,
@@ -238,29 +223,34 @@ const buildMetaTransactionForEjection = async (
     );
   }
 
-  if (typeof transactionRequest.nonce === 'undefined') {
+  const metaTransaction: MetaTransaction = {
+    to: transactionRequest.to.toString(),
+    data: transactionRequest.data,
+    value: transactionRequest.value,
+    revertOnError: true,
+  };
+
+  return metaTransaction;
+};
+
+const parseNonce = (transactionRequest: TransactionRequest): bigint => {
+  if (typeof transactionRequest.nonce === 'undefined' || transactionRequest.nonce === null) {
     throw new JsonRpcError(
       RpcErrorCode.INVALID_PARAMS,
       'im_signEjectionTransaction requires a "nonce" field',
     );
   }
+  return BigInt(transactionRequest.nonce);
+};
 
-  if (!transactionRequest.chainId) {
+const parseChainId = (transactionRequest: TransactionRequest): bigint => {
+  if (typeof transactionRequest.chainId === 'undefined' || transactionRequest.chainId === null) {
     throw new JsonRpcError(
       RpcErrorCode.INVALID_PARAMS,
       'im_signEjectionTransaction requires a "chainId" field',
     );
   }
-
-  const metaTransaction: MetaTransaction = {
-    to: transactionRequest.to.toString(),
-    data: transactionRequest.data,
-    nonce: transactionRequest.nonce ?? undefined,
-    value: transactionRequest.value,
-    revertOnError: true,
-  };
-
-  return [metaTransaction];
+  return BigInt(transactionRequest.chainId);
 };
 
 export const prepareAndSignEjectionTransaction = async ({
@@ -269,15 +259,17 @@ export const prepareAndSignEjectionTransaction = async ({
   zkEvmAddress,
   flow,
 }: EjectionTransactionParams & { transactionRequest: TransactionRequest }): Promise<EjectionTransactionResponse> => {
+  const nonce = parseNonce(transactionRequest);
+  const chainId = parseChainId(transactionRequest);
   const metaTransaction = await buildMetaTransactionForEjection(
     transactionRequest,
   );
   flow.addEvent('endBuildMetaTransactions');
 
   const signedTransaction = await signMetaTransactions(
-    metaTransaction,
-    transactionRequest.nonce as BigNumberish,
-    BigInt(transactionRequest.chainId ?? 0),
+    [metaTransaction],
+    nonce,
+    chainId,
     zkEvmAddress,
     ethSigner,
   );
diff --git a/packages/passport/sdk/src/zkEvm/types.ts b/packages/passport/sdk/src/zkEvm/types.ts
index b013685712..b29c0699ff 100644
--- a/packages/passport/sdk/src/zkEvm/types.ts
+++ b/packages/passport/sdk/src/zkEvm/types.ts
@@ -30,7 +30,6 @@ export interface MetaTransaction {
   to: string;
   value?: BigNumberish | null;
   data?: string | null;
-  nonce?: BigNumberish;
   gasLimit?: BigNumberish;
   delegateCall?: boolean;
   revertOnError?: boolean;
diff --git a/packages/passport/sdk/src/zkEvm/walletHelpers.test.ts b/packages/passport/sdk/src/zkEvm/walletHelpers.test.ts
index 375650eff2..f49527aabb 100644
--- a/packages/passport/sdk/src/zkEvm/walletHelpers.test.ts
+++ b/packages/passport/sdk/src/zkEvm/walletHelpers.test.ts
@@ -31,13 +31,13 @@ describe('signMetaTransactions', () => {
         data: '0x',
       },
     ];
-    const nonce = 0;
-    const chainId = 1779;
+    const nonce = 0n;
+    const chainId = 1779n;
 
     const signature = await signMetaTransactions(
       transactions,
       nonce,
-      BigInt(chainId),
+      chainId,
       walletAddress,
       signer,
     );
diff --git a/packages/passport/sdk/src/zkEvm/walletHelpers.ts b/packages/passport/sdk/src/zkEvm/walletHelpers.ts
index da5a9dcdc3..5d2c786ebc 100644
--- a/packages/passport/sdk/src/zkEvm/walletHelpers.ts
+++ b/packages/passport/sdk/src/zkEvm/walletHelpers.ts
@@ -114,7 +114,7 @@ export const encodeMessageSubDigest = (chainId: bigint, walletAddress: string, d
 
 export const signMetaTransactions = async (
   metaTransactions: MetaTransaction[],
-  nonce: BigNumberish,
+  nonce: bigint,
   chainId: bigint,
   walletAddress: string,
   signer: Signer,