"We have detected unusual activity on your account" and now can't log in across any platforms

The message indicates Microsoft has blocked or restricted the account due to unusual or risky sign‑in activity. When that happens, access is only restored after successfully completing the security verification flow.

Because the normal verification option (code sent to the same email account) is not usable, follow these supported paths:

1. Respond to the unusual‑activity challenge
   • On the sign‑in page where the warning appears, follow the on‑screen steps to choose where to receive a security code.
   • If any alternate method is listed (phone number, alternate email, trusted device), select that instead of the locked mailbox and complete the verification.
   • After entering the code, finish any required password‑change step.
2. If no usable verification option works
   • The block is tied to protecting the account from suspicious activity. In this case, use the account recovery process and/or wait for the temporary block to clear:
     • If the page shows a link that begins with aka.ms/ (for example when the account is locked), select it and follow the instructions to submit the requested information so Microsoft can review and unlock the account.
     • If you repeatedly requested codes or attempted sign‑in many times, a temporary block may apply. Avoid further attempts and wait at least 24 hours (up to several days) before trying again, as repeated attempts can reset the timer.
3. Try alternative verification methods and networks
   • If the sign‑in flow shows Try another verification method, use any other method on the account (alternate email, SMS, authenticator, etc.).
   • If you keep hitting a block, switch network (for example, from office Wi‑Fi to mobile data) and try again later, as heavy suspicious traffic from a location can also cause temporary blocking.
4. If still unable to sign in
   • Use the sign‑in helper/troubleshooter referenced in the verification‑code troubleshooting article to identify the exact issue and see available support options.
   • For a work or school account (Microsoft Entra ID), contact the organization’s IT administrator or Help desk and ask them to review Microsoft Entra sign‑in logs and unblock or assist with MFA/verification.

If none of the available verification options are accessible and the recovery process does not succeed, support agents cannot bypass these automated protections for consumer Outlook.com/Hotmail accounts; continued attempts must go through the official recovery and sign‑in helper flows.

References:

• What happens if there's an unusual sign-in to your account
• Troubleshoot Microsoft verification code issues
• Microsoft account has been locked