To save a backup copy of your tax data file (.tax file) that can be opened and read by TurboTax Desktop software, follow the instructions for your TurboTax product:
Another option is saving a copy of your tax return as a PDF file, which is like a picture of your tax return that you can view or print. It may sound similar to a .tax file, but they're very different.
PDF files cannot be opened or read by TurboTax software, which means they cannot be used for amending or troubleshooting calculation issues.