Correct the phone number associated with my account

The key thing to understand is: you usually can’t change the phone number until you successfully sign in, so the solution depends on whether you can still access your account another way.

When signing in to your Microsoft Surface Book or any Microsoft device:

Click “I don’t have access to this number” or “Use another verification option”

Try:

Alternate email address (if added earlier)

Authenticator app (if you ever set up Microsoft Authenticator)

Backup codes (if saved earlier)

If any of this works, you can log in and then update your phone number immediately.

Another option:

Go to the official recovery page: https://account.live.com/acsr

Enter your email and fill out the form carefully

Provide as details as possible.

Once you can log in you will be able to remove old phone no. and add the new. Turn on 2-step verification.

To fix sign-in issues caused by an old or incorrect phone number, update the phone number on the Microsoft account and, if applicable, in the work/school security info used for verification codes.

1. Update the phone number on the Microsoft account (personal account)
   1. Go to the Microsoft account aliases page: https://account.live.com/names/manage.
   2. Sign in with the same Microsoft account used on the Surface Book.
   3. Under Your info, choose Add phone number to add the current mobile number, or select Remove next to the old number to delete it.
   4. Follow the prompts to verify the new number (a code will be sent to that number once it is entered correctly).
   Verification codes sent by email can only be sent to the primary alias or another email added as a way to verify sign in. Make sure the correct phone or email is listed as security info.
2. If using a work or school account (Azure AD / Microsoft 365) If the Surface is joined to an organization and uses a work or school account, update the security verification methods there:
   1. Open a browser and go to the Security info page for the work/school account (for example, via the Additional security verification or Security info link your organization provides).
   2. Sign in with the work or school account.
   3. Remove the old phone number:
      • Tab or navigate until the phone method is selected (for example, "Security info type, phone, delete phone"), then choose Delete and confirm.
   4. Add the new phone number:
      • Choose Add sign-in method.
      • Select Phone as the method.
      • Enter the new mobile number and complete the verification steps.
3. If codes still do not arrive after updating the number If the number is correct but SMS codes are not being received:
   • Avoid repeatedly requesting new codes; excessive or repetitive requests can cause a temporary block where codes are not sent.
   • Check whether the phone blocks texts from unknown numbers and, if so, allow them and then choose I don't have a code to trigger a new one.
   • Ensure the number is a mobile number, not a VOIP number; VOIP numbers cannot be used to receive Microsoft verification codes.
   • Check that the phone’s SMS inbox is not full and that the messaging app is working properly.
   • If there is heavy compromised traffic from the region, delivery may be delayed; this usually resolves automatically after some time.

Once the phone number is corrected and verified in the account’s security info, sign-in prompts on the Surface Book that send text codes should start using the new number.

References:

• Change the email address or phone number for your Microsoft account
• Use a screen reader to set up and troubleshoot multifactor authentication
• Common problems with two-step verification for a work or school account
• Troubleshoot Microsoft verification code issues