Account lockout/ Account not found

The custom @yourdomain.onmicrosoft.com address created during Microsoft 365 Business signup is a work/school (Microsoft 365 for business) account, not a personal Microsoft account. It is managed in Azure AD/Microsoft Entra ID for that new tenant.

Because the signup was interrupted, the situation is typically one of these:

1. The @yourdomain.onmicrosoft.com account exists as an organizational account, but is not a personal Microsoft account, so consumer sign-in and consumer password reset flows show “account doesn’t exist.”
2. The tenant or account creation did not fully complete, so the address is reserved in the directory but not usable through normal self-service recovery.

Self-service recovery (the normal Microsoft account tools) will not work for this kind of business account:

• The article on forgotten Microsoft account usernames and sign-in issues applies to personal Microsoft accounts, not to new onmicrosoft.com business tenants. For personal accounts, the guidance is to:
  • Use the Sign-in Helper tool if the email/username is forgotten.
  • Use the account recovery form or password reset if the password is forgotten.
  • If the error is “We couldn't find an account with that username” or “account doesn't exist,” verify spelling and domain and confirm whether the address is actually a Microsoft account.
• For business tenants, those tools do not manage the initial global admin @tenant.onmicrosoft.com account created during signup.

Given that:

1. Check whether the email is a Microsoft account at all
   • Go to https://account.microsoft.com and enter the @yourdomain.onmicrosoft.com address as described in “How to check if your email address is a Microsoft account.”
   • If it shows a password prompt, it is recognized as a Microsoft account (consumer). In that case, use the standard recovery flows:
     • If the password is forgotten, use the password reset flow.
     • If the username or password has stopped working, use the “Recover your account” option and follow the steps to reset the password.
   • If it shows “We couldn't find an account with that username” or “That Microsoft account doesn't exist,” then it is not a consumer Microsoft account, and the consumer recovery tools cannot be used.
2. If it is not a consumer Microsoft account
   • Then it is either:
     • A business account in a Microsoft 365 tenant that did not complete setup, or
     • A partially created tenant where only Microsoft’s backend can finalize or clean up the admin account.
   • In this case, self-service recovery is not available. The only path is through Microsoft support for business/tenant identity issues.
3. Next steps with support
   • When contacting support, clearly state:
     • This is a Microsoft 365 for business signup issue.
     • A new tenant and admin account @yourdomain.onmicrosoft.com were created during purchase, but the signup was interrupted.
     • The system now says the account already exists, but sign-in and password reset for that address report “account doesn’t exist.”
   • Ask support to:
     • Locate the tenant associated with the @yourdomain.onmicrosoft.com domain.
     • Confirm whether the global admin account was created and is active.
     • Help either complete the tenant setup or release/reset the admin account so it can be accessed.

If the address had instead been a personal Microsoft account (for example, if the same email was used previously as a Microsoft account), the documented steps would be:

• Use the “Recover your account” flow at https://account.live.com/password/reset with the email, phone, or Skype name.
• If the username and password have stopped working, follow the “My username and password have stopped working” steps:
  • Enter the sign-in identifier.
  • Receive a security code via a configured method.
  • Enter the code and set a new password.
• If the message “We couldn't find an account with that username” persists, verify spelling and domain and, if still failing, contact support via the “Contact support” option in that article.

However, because this is a new onmicrosoft.com business admin account created during tenant signup, recovery must be handled as a business tenant identity case by Microsoft support rather than through consumer self-service tools.

References:

• I forgot the account I use with Microsoft 365
• I can't sign in to my Microsoft account
• My username and password have stopped working
• How to check if your email address is a Microsoft account