If you've already filed your income tax return, you can't go back in and change your telephone number.
- Also, you can't enter a foreign phone number in TurboTax.
If you need to update your phone number for your TurboTax Account, before you file your income tax return:
- Log in to your account.
- On the left side menu, select My Info.
- On the Personal info summary screen, scroll down to Mailing address and select Edit.