diff --git a/src/modules/call/call.controller.ts b/src/modules/call/call.controller.ts
index 932e18d..b02f3a8 100644
--- a/src/modules/call/call.controller.ts
+++ b/src/modules/call/call.controller.ts
@@ -119,12 +119,15 @@ export class CallController {
     @Body() joinCallDto?: JoinCallDto,
   ): Promise<JoinCallResponseDto> {
     const { uuid, email } = user || {};
+    const isUserAnonymous =
+      (!!joinCallDto?.anonymousId || joinCallDto?.anonymous) ?? !user;
 
     return await this.callUseCase.joinCall(roomId, {
       userId: uuid,
       name: joinCallDto?.name,
       lastName: joinCallDto?.lastName,
-      anonymous: joinCallDto?.anonymous || !user,
+      anonymous: isUserAnonymous,
+      anonymousId: joinCallDto?.anonymousId,
       email: email,
     });
   }
diff --git a/src/modules/call/call.usecase.ts b/src/modules/call/call.usecase.ts
index cdd8c45..27a43d0 100644
--- a/src/modules/call/call.usecase.ts
+++ b/src/modules/call/call.usecase.ts
@@ -1,11 +1,12 @@
 import {
+  BadRequestException,
   ConflictException,
   ForbiddenException,
   Injectable,
   Logger,
   NotFoundException,
 } from '@nestjs/common';
-import { v4 as uuidv4 } from 'uuid';
+import { v4 } from 'uuid';
 import { UserTokenData } from '../auth/dto/user.dto';
 import { RoomService } from './services/room.service';
 import { Room } from './domain/room.domain';
@@ -73,6 +74,7 @@ export class CallUseCase {
       name?: string;
       lastName?: string;
       anonymous?: boolean;
+      anonymousId?: string;
       email?: string;
     },
   ): Promise<JoinCallResponseDto> {
@@ -81,28 +83,55 @@ export class CallUseCase {
       throw new NotFoundException(`Specified room not found`);
     }
 
-    const processedUserData = this.processUserData(userData);
-    const isOwner = processedUserData.userId === room.hostId;
+    const joiningUserData = {
+      userId: userData?.anonymous
+        ? (userData?.anonymousId ?? v4())
+        : userData?.userId,
+      name: userData?.name,
+      lastName: userData?.lastName,
+      anonymous: userData?.anonymous || !userData.userId,
+      email: userData?.email,
+    };
+
+    const isOwner = joiningUserData.userId === room.hostId;
 
     if (!isOwner && room.isClosed) {
       throw new ForbiddenException('Room is closed');
     }
 
-    const roomUser = await this.roomService.addUserToRoom(
-      roomId,
-      processedUserData,
+    const existentUserInRoom = await this.roomService.getUserInRoom(
+      joiningUserData.userId,
+      room.id,
     );
 
+    const currentUsersCount = await this.roomService.countUsersInRoom(room.id);
+
+    const isRoomFull = currentUsersCount >= room.maxUsersAllowed;
+
+    if (isRoomFull && !existentUserInRoom) {
+      throw new BadRequestException('The room is full');
+    }
+
+    const roomUser =
+      existentUserInRoom ??
+      (await this.roomService.createUserInRoom({
+        roomId: room.id,
+        userId: joiningUserData?.userId,
+        name: joiningUserData?.name,
+        lastName: joiningUserData?.lastName,
+        anonymous: Boolean(joiningUserData?.anonymous),
+      }));
+
     // Generate token for the user
     const tokenData = this.callService.createCallTokenForParticipant(
       roomUser.userId,
       roomId,
       !!roomUser.anonymous,
       isOwner,
-      processedUserData,
+      joiningUserData,
     );
 
-    if (processedUserData.userId === room.hostId && room.isClosed) {
+    if (joiningUserData.userId === room.hostId && room.isClosed) {
       await this.roomService.openRoom(roomId);
     }
 
@@ -114,39 +143,6 @@ export class CallUseCase {
     };
   }
 
-  private processUserData(userData: {
-    userId?: string;
-    name?: string;
-    lastName?: string;
-    anonymous?: boolean;
-    email?: string;
-  }): {
-    userId: string;
-    name?: string;
-    lastName?: string;
-    anonymous: boolean;
-    email?: string;
-  } {
-    const { userId, name, lastName, anonymous = false, email } = userData;
-
-    if (anonymous || !userId) {
-      return {
-        userId: uuidv4(),
-        name,
-        lastName,
-        anonymous: true,
-      };
-    }
-
-    return {
-      userId,
-      name,
-      lastName,
-      anonymous: false,
-      email,
-    };
-  }
-
   async leaveCall(roomId: string, userId: string): Promise<void> {
     const room = await this.roomService.getRoomByRoomId(roomId);
 
diff --git a/src/modules/call/dto/join-call.dto.ts b/src/modules/call/dto/join-call.dto.ts
index b26aa6a..8f2b617 100644
--- a/src/modules/call/dto/join-call.dto.ts
+++ b/src/modules/call/dto/join-call.dto.ts
@@ -1,5 +1,5 @@
 import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
-import { IsBoolean, IsOptional, IsString } from 'class-validator';
+import { IsBoolean, IsOptional, IsString, IsUUID } from 'class-validator';
 
 export class JoinCallDto {
   @ApiPropertyOptional({
@@ -21,12 +21,21 @@ export class JoinCallDto {
   @ApiPropertyOptional({
     description: 'Whether the user is joining anonymously',
     type: Boolean,
-    default: false,
+    deprecated: true,
   })
   @IsBoolean()
   @IsOptional()
   anonymous?: boolean;
 
+  @ApiPropertyOptional({
+    description: 'Id to use for anonymous user',
+    type: String,
+    required: false,
+  })
+  @IsUUID()
+  @IsOptional()
+  anonymousId?: string;
+
   @IsString()
   @IsOptional()
   email?: string;
diff --git a/src/modules/call/services/room.service.ts b/src/modules/call/services/room.service.ts
index 12c7662..c5d8155 100644
--- a/src/modules/call/services/room.service.ts
+++ b/src/modules/call/services/room.service.ts
@@ -7,7 +7,7 @@ import {
 import { SequelizeRoomRepository } from '../infrastructure/room.repository';
 import { SequelizeRoomUserRepository } from '../infrastructure/room-user.repository';
 import { Room, RoomAttributes } from '../domain/room.domain';
-import { RoomUser } from '../domain/room-user.domain';
+import { RoomUser, RoomUserAttributes } from '../domain/room-user.domain';
 import { v4 as uuidv4 } from 'uuid';
 import { UsersInRoomDto } from '../dto/users-in-room.dto';
 import { UserRepository } from '../../../shared/user/user.repository';
@@ -27,6 +27,10 @@ export class RoomService {
     return this.roomRepository.create(data);
   }
 
+  async createUserInRoom(data: Omit<RoomUserAttributes, 'id'>) {
+    return this.roomUserRepository.create(data);
+  }
+
   async getRoomByRoomId(id: RoomAttributes['id']) {
     return this.roomRepository.findById(id);
   }
@@ -59,7 +63,7 @@ export class RoomService {
   }
 
   async addUserToRoom(
-    roomId: string,
+    room: Room,
     userData: {
       userId?: string;
       name?: string;
@@ -67,27 +71,19 @@ export class RoomService {
       anonymous?: boolean;
     },
   ): Promise<RoomUser> {
-    const room = await this.getRoomByRoomId(roomId);
-    if (!room) {
-      throw new NotFoundException(`Specified room not found`);
-    }
+    const currentUsersCount = await this.roomUserRepository.countByRoomId(
+      room.id,
+    );
 
-    const currentUsersCount =
-      await this.roomUserRepository.countByRoomId(roomId);
     if (currentUsersCount >= room.maxUsersAllowed) {
       throw new BadRequestException('The room is full');
     }
 
     const { userId, name, lastName, anonymous = false } = userData;
-    let userIdToUse = userId;
-
-    if (anonymous || !userIdToUse) {
-      userIdToUse = uuidv4();
-    }
 
     const existingUser = await this.roomUserRepository.findByUserIdAndRoomId(
-      userIdToUse,
-      roomId,
+      userId,
+      room.id,
     );
 
     if (existingUser) {
@@ -95,8 +91,8 @@ export class RoomService {
     }
 
     return this.roomUserRepository.create({
-      roomId,
-      userId: userIdToUse,
+      roomId: room.id,
+      userId,
       name,
       lastName,
       anonymous: Boolean(anonymous),
@@ -159,4 +155,13 @@ export class RoomService {
 
     return userAvatars;
   }
+
+  async getUserInRoom(userId: string, roomId: string) {
+    const existingUser = await this.roomUserRepository.findByUserIdAndRoomId(
+      userId,
+      roomId,
+    );
+
+    return existingUser;
+  }
 }