If the goal is to add a phone number for sign-in to a personal Microsoft account, use the Account info/Profile area, not the Security verification area:
- Open
https://account.microsoft.com/profile - Under Account info, go to Phone number
- Select Add your phone number
If the goal is to add a phone number for security verification, Microsoft may no longer offer phone as a new verification method for some personal accounts. In that case:
- Go to
https://account.microsoft.com/security - Select Manage how I sign in
- Select Add a new way to sign in or verify
- If phone is not offered, use one of the available methods such as a recovery email address, Microsoft Authenticator, or a passkey
If the option to add a phone number is missing or the number will not add:
- Make sure the number is not already linked to another Microsoft account
- Try an incognito/private browser window
- Try a different browser, clear cache/cookies, or use a different device/network
- If a message says the number is already taken or already used to sign in, remove it from the other Microsoft account first, then add it to the intended account
- If there is no Transfer option, the number may have been used recently on another account. In that case, use a different number, or try again after 30 days if the number is new
Important details:
- A phone number can only be added to a single Microsoft account
- Only one mobile number can be used as a sign-in alias
- The option to add a new phone number may not appear for security verification on some accounts
If help is still needed, use Microsoft Support from the account support pages.
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