I get Error Code 603 when I try to activate TurboTax 2020 when I need to amend a return. What should I do?

[dana]

It says all available activations have been used.

[PatriciaV]

Software for tax years 2020 and earlier is no longer supported by TurboTax (as of 2023). You may be able to find another software program or a local tax professional to prepare an amended return. Note that you have three years from the date you filed your return or two years after you paid the tax due (whichever is later) to file an amendment. Some exceptions apply, like bad debt, worthless securities, foreign tax credit, or an IRS audit.

If you choose to purchase software from a vendor other than TurboTax, we caution you to use due diligence to ensure it is a legitimate vendor.