How to change my phone number

To change the phone number on the Microsoft account used for Windows sign-in and security, the phone number must be managed as an alias/security info on the Microsoft account, not from Windows directly.

Follow these steps in order:

1. Add or confirm an email alias on the Microsoft account
   1. Go to Manage how you sign in to Microsoft: https://account.live.com/names/manage and sign in.
   2. Under Account alias / Your info, confirm that at least one email address is listed.
   3. If no email is listed, choose Add email, follow the prompts to add and verify an email address.
2. Add the new phone number as an alias
   1. On the same page (https://account.live.com/names/manage), choose Add phone number.
   2. Enter the new mobile number and follow the verification prompts (code by SMS).
   3. Optionally, set the new number or an email as Make primary if desired.
3. Remove or change the old phone number
   1. Still on the alias page, select Remove next to the old phone number.
   2. If the old phone number is the primary alias, first make another email or phone number primary, then remove the old number.
4. Update security verification methods (used for codes and MFA)
   1. Go to Advanced security options of the Microsoft account: https://go.microsoft.com/fwlink/?linkid=2204804 and sign in.
   2. Under Security info / verification methods, add the new phone number if it is not already listed.
   3. Only after adding the new phone number, expand the old phone method and select Remove, then confirm.
   4. Do not remove all security info at once; if all security info is removed, the account goes into a 30‑day restricted state where changes are blocked.
5. If the system says an email is required before removing the phone
   1. Ensure at least one email alias exists and is verified on https://account.live.com/names/manage.
   2. If the page still does not show Add phone number, use the guided support tool linked in the article about changing email/phone for the Microsoft account to troubleshoot sign-in and alias issues.
6. If the phone number is already used on another Microsoft account
   1. When adding the new number, if the message says the phone number is already a Microsoft account or already used to sign in, choose one of the options:
      • Sign in if that number belongs to another account owned.
      • Transfer number to move it to the current account, and follow the prompts.
      • If Transfer number is not available, select Change number and either wait 30 days or use a different number.
7. After changes, re‑sign into Windows
   1. Sign out of Windows, then sign back in with the Microsoft account.
   2. If Windows Hello PIN prompts issues persist, use the updated phone/email security info to receive codes, then reset the PIN if needed.

If still blocked by verification (for example, codes not arriving or security info mismatch), use the I don't have any of these option on the verification screen to replace security info, understanding that replacing all security info triggers a 30‑day protection period where security changes are locked.

References:

• How do I change or remove my phone number in Skype?
• Help with "phone number is already used" in a Microsoft account
• Use a screen reader to set up and troubleshoot multifactor authentication
• Change the email address or phone number for your Microsoft account
• Removing a sign-in verification method
• Change your phone number or email address in Microsoft Teams Free
• Keeps prompting "Add a recovery phone number" but my phone is already added for recovery - Microsoft Q&A
• Please confirm my e mail address as <removed PII>@outlook.com - Microsoft Q&A