You can update your phone number from the Account settings screen in Handoff.
Steps to Change Your Phone Number
Open Handoff and go to Settings.
Tap Account settings.
Under Account Information, tap the Phone number field.
Clear the current number and enter your new US phone number.
Tap outside the field (or press Done on mobile).
A verification prompt will appear — enter the code sent to your new number to confirm.
Important Notes
Handoff supports US phone numbers only. Canadian and international numbers are not supported.
Your phone number is used to log in to Handoff, so make sure it is a number you have access to.
After changing your number, you will use the new number to log in going forward.
Having Trouble?
If the verification code does not arrive, tap Resend to request a new one. If you continue to have issues, contact Handoff support via the chat icon in the app.