Would someone know how to attach PDFs files when e-filing the tax return? Should it be done at the final step "File Return" or before?
A PDF cannot be attached to an e-filed tax return using TurboTax. The tax return would have to be printed and mailed to include the PDF.
What exactly are you needing to attach to the tax return?
It is related to Schedule 3 - Part II - (12D) Claim of Right, IRC 1341.
I manually calculated the overpaid tax on previous year (2021).
Now I need to attach the "overpayment letter" and calculation files saved as PDF.
Then you will have to print and mail your tax return to include this information.