The missing Add phone number option is on the sign-in-alias page, and the available documentation does not provide another self-service route for adding a phone alias when that option is absent.
What the page is managing
Manage how you sign in to Microsoft manages aliases—email addresses or phone numbers that can be used as usernames for the same personal Microsoft account. Microsoft’s instructions normally show Add email and Add phone number there.[^1^](https://support.microsoft.com/outlook/something-went-wrong-with-error-addriverstoreaccessnonlocalexception#add-another-alias-to-your-account-and-make-it-the-primary-alias ""Something went wrong" with error ADDriverStoreAccessNonLocalException | Microsoft Support")
That is separate from Security → Manage how I sign in, which manages verification and account-recovery methods. Microsoft is phasing out SMS authentication for personal accounts, so this Security page may offer only:
- A recovery email
- Microsoft Authenticator
- A passkey
Microsoft explicitly states that Add a new phone number might not be available as a security method.^2^ This SMS change explains missing phone options on the Security page, but it does not establish why the phone-alias option is missing from your Your info page.
What to do now
- Protect account recovery first, because the old number has already been removed:
- Open the Microsoft account Security page.
- Select Manage how I sign in.
- Select Add a new way to sign in or verify.
- Add a recovery email, Microsoft Authenticator, or a passkey.^2^
A verification email does not have to be a new Outlook address; it can be another accessible email address. It is different from selecting Add email on the aliases page.
- For the missing phone-alias control, contact Microsoft Support:
- Enter the problem as: “Add phone number is missing under Manage how you sign in to Microsoft for my personal Microsoft account.”
- Select Get Help, then Contact Support if offered.
Microsoft directs unresolved account-number issues to Support, although support agents cannot directly access or change account details.^3^
Do not remove any remaining recovery method until at least one replacement method has been added and tested. Microsoft is moving personal accounts away from SMS because of phishing and SIM-swap risks, favoring verified email and passkeys instead.^4^
References
- "Something went wrong" with error ADDriverStoreAccessNonLocalException | Microsoft Support
- Microsoft account security info & verification codes | Microsoft Support
- Help with reusing phone numbers in a Microsoft account | Microsoft Support
- Microsoft to stop sending SMS codes for personal accounts