Microsoft account phone number on new account

Question

Went to login to my account with my phone number as always and my phone number asked to send a code to a email I've never used before.

Used email password was the same and updated. My phone number was always linked to theis account and used this email for 20 years, the account its linked to now says yahoo, I have never had a yahoo.com

I logged into my microsoft account after changing password and trying to see what phone number is linked to my account but cant find it anywhere to see the associated number

Answer 1

The behavior described indicates that the phone number is already associated as an alias/sign-in method on a different Microsoft account than the one expected.

When a phone number is used to sign in and Microsoft shows an unfamiliar email address (for example, a Yahoo address) and asks to send a code there, it means:

• That phone number is currently an alias/security info on that other Microsoft account.
• The sign-in flow is trying to verify identity using the security info stored on that account.

To address this:

1. Verify which account the phone number belongs to
   • When seeing the message that the phone number is already used, look for options like Sign in, Continue, or Transfer number.
   • If the phone number is already an alias for another Microsoft account owned by the user, it can be used directly to sign in to that account instead of the long‑used email.
2. Move the phone number to the correct account (if both accounts are owned by the user)
   • If the phone number is associated with a different Microsoft account and should be used on the long‑used account instead:
     • When prompted with a message like "[phone number] is already a Microsoft account" or "We noticed [phone number] is already used to sign in to [another number]", choose:
       • Sign up or Transfer number (if shown) to move the phone number from the existing account to the intended account, and follow the prompts.
     • If the Transfer number option does not appear, it may be because the phone number was recently used on another account. In that case, wait 30 days and try again.
3. Check and manage aliases on the known Microsoft account
   • Sign in to the known Microsoft account’s “how you sign in” page: Edit account info.
   • Under Your info, review:
     • Email addresses and phone numbers listed as aliases.
     • Use Add phone number or Add email to add new aliases.
     • Use Remove next to any alias that should not be there.
4. If the email shown is not recognized and access is blocked
   • If the email domain or address shown for verification is not recognized, and sign-in cannot be completed using any known alias or security info, use the account recovery path:
     • Go to the Microsoft account recovery page via Recover your account and follow the prompts with any known email, phone, or Skype name.
   • If still unable to sign in or the system reports that the username cannot be found, contact support using the Contact support option provided in the sign-in help.
5. Understand aliases and security info
   • Phone numbers and email addresses on a Microsoft account are aliases and share the same password.
   • Any alias (including phone number) can be used to sign in.
   • Security info (phone/email) is used for verification codes; if an unfamiliar email appears, it means that email is stored as security info on the account currently being accessed.

If none of the aliases or security info shown are recognized, and recovery options fail, the only supported path is to use the guided recovery tools and, if needed, contact Microsoft support through the provided links.

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References:

• Help with "phone number is already used" in a Microsoft account
• How to add an email address or phone number to your Microsoft account
• Change the email address or phone number for your Microsoft account
• My username and password have stopped working
• Common problems with two-step verification for a work or school account
• Troubleshoot Microsoft verification code issues
• Help us secure your account