I just e-file my 2020 return and it was accepted. I then realized I had made a mistake in my favor. How do I amend?

If you have already filed your return you have the option to "recall" your filed tax return.

If you want to review and update your 2020 return, please enter your information here by February 6, to have your 2020 tax return sent back to you.  You will then receive an email from TurboTax on February 8, letting you know that your return is available and providing you with detailed instructions on how to review, update and re-file your tax return.

Other than that you will need to wait and see if your return gets accepted or rejected. Please be aware that the IRS currently won't start processing returns until February 12, 2021.

• If your return will be rejected by the IRS, then all you have to do is make the changes on your return and refile.
• If your return gets accepted you will have to wait and see if you receive your refund that includes the additional credit. If yes then you will need to amend your return and send the funds back to the IRS. Please see  FAQ How to amend a tax return for instructions.
   
  But the IRS has not addressed the details yet. They will not open until February 12 and you would not be able to amend until that time and in the meantime, the IRS may establish a guideline. Please see this IRS Recovery Rebate Credit for more information.