Received a single-use code that I did not request- what to do?

Question

Hi,

I received a single-use code last night (May 15th) around 10PM that I did NOT request. Honestly, I wasn't not aware that I had a Microsoft account linked to my personal email. I tried getting support via Microsoft's live chat, which seemed to be down, and then from a JustAnswers site that wanted me to enter my card information to receive help, which I thought was not right. So I logged in with my personal email address to see if I can get any insights on 1) why did I receive a single-use code that I did not request, 2) is this account (that I did not know I had) risked of anything, and 3) how can I check account activity.

Thanks

Answer 1

Hello, this is Emily.

Sign into the account here: https://account.microsoft.com, then go to Security to review the sign in activities. When you reviewed the account's sign in activities, Click into those labeled as "unsuccessful sign in", you can click on it to expand it to review the Session activity. If it is incorrect password, it won't generate a code. And there's nothing to worry about. If it is request denied xxx, that means this activity had your password entered correctly, and a code was generated, but it didn't pass the two factor verification. In the latter scenario, you want to change the password asap.

If you can NOT find any unsuccessful sign-in with the "request denied" labeling, it can mean that someone else left your contact information as their security info, usually due to typo. In this case, your account is not in any danger. Unfortunately there's also nothing you can do about it until this other user realized they needed to update their contact info.

Another way to find out which scenario is yours is to go to the account https://account.microsoft.com click on Security > Advanced Security options, set up authentication app instead. That way, if you continue to receive code via text or email instead, you would know 100% that it is NOT about your account, but someone else left your phone/email as their contact info due to typo.

Answer 2

A single-use (verification) code that was not requested usually means one of the following:

1. Someone is trying to access the account using that email or phone number.
2. Someone mistyped their email/phone and accidentally entered this one.
3. A code that was legitimately requested earlier was delayed and arrived later than expected.

Do not enter or share the code if it was not requested. Without the code, an attacker cannot complete sign-in, so the account remains protected.

To reduce risk and check the situation:

1. Sign in directly and securely
   • If concerned, sign in by manually entering https://account.microsoft.com or https://account.live.com in a browser (do not use links in emails or texts).
   • This ensures any sign-in or security changes are done on the legitimate Microsoft site.
2. Check and secure the account
   • Once signed in, review security info (phone, email, sign-in methods) and remove anything not recognized.
   • Consider turning on two-step verification and/or going passwordless using methods like Microsoft Authenticator, Windows Hello, SMS/email codes, or security keys.
3. Ignore further unrequested codes
   • If more unrequested codes arrive, continue to ignore them. Do not respond or use them.
   • The guidance is to not respond to any codes that were not requested; without the code, the account is safe.

If unrequested codes continue frequently, enabling passwordless sign-in and strong multifactor methods helps secure the account and reduce reliance on one-time codes.

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References:

• Troubleshoot Microsoft verification code issues
• Common problems with two-step verification for a work or school account
• Why is Microsoft texting me?