You only need the tax return data file ending in .tax2023 to transfer into 2024 or .tax2024 to transfer into next year.
To backup your tax return data files. What I would do is copy the whole Turbo Tax folder that is under your Documents. That should be where the .tax files and pdf files are stored. Copy that folder to a flash drive or external drive, etc.
I bought Turbo Tax from Costco. Before I upgraded my Windows 10 to 11 I backed up my data files just in case. When I upgraded all my programs (back to 2019) were still there and worked. And all my tax return files were there and opened.
