diff --git a/apps/api/src/account/account.service.ts b/apps/api/src/account/account.service.ts
index f4d5181..39ec7b5 100644
--- a/apps/api/src/account/account.service.ts
+++ b/apps/api/src/account/account.service.ts
@@ -18,6 +18,13 @@ export class AccountService {
   ) {}
 
   public async create(createAccountDto: CreateAccountDto): Promise<Account> {
+    const isExist = await this.accountModel.exists({ username: createAccountDto.username }).exec();
+
+    if (isExist)
+      throw new BadRequestException(
+        `Account with username '${createAccountDto.username}' already exists`
+      );
+
     Object.keys(createAccountDto).forEach((field) => {
       if (['_id', '__v'].includes(field))
         throw new BadRequestException(`Prop ${field} is not allowed`);