change my phone number

Because your work or school account does not allow you to edit the profile phone number, ask your organization’s Microsoft 365 administrator or IT help desk to update the Contact information field for your account.

Administrator steps

Give the administrator your new number and ask them to:

1. Sign in to the Microsoft 365 admin center.
2. Go to Users → Active users.
3. Select your account.
4. On the Account tab, select Manage contact information.
5. Enter the new phone number and select Save changes. ^1^

Your organization can restrict which profile fields users may edit, so repeatedly returning to your account-information page will not help when self-service editing has been disabled. ^2^

If the administrator cannot edit it

The account may be synchronized from an on-premises directory. For directory-synchronized users, the administrator must change the phone number in the organization’s on-premises directory tools, rather than in Microsoft 365; the updated value then synchronizes to Microsoft 365. ^2^

If this is also your sign-in verification number

The profile/contact number and the number used for multifactor authentication are separate settings. To change the verification number:

1. Open https://mysignins.microsoft.com/security-info.
2. Sign in with the work or school account.
3. Select Add sign-in method and add the new phone.
4. Verify it, then remove the old phone.

If sign-in only offers the inaccessible old number, contact your organization’s IT help desk; the tenant administrator must reset your authentication methods so that you can register the new number. ^3^

If this is your own Microsoft 365 administrator account

Go to Microsoft 365 admin center → Users → Active users → select your administrator account → Manage contact information, update the number, and select Save changes. ^4^

References

1. Change a user name and email address
2. How to update contact information in Exchange Online in Microsoft 365
3. How to change my phone number - Microsoft Q&A
4. Update your Microsoft 365 admin phone number and email address