If you want to file for free you can fill out the forms by hand. Here are some basic forms…..
Here is the IRS 2020 Form 1040
https://www.irs.gov/pub/irs-prior/f1040--2020.pdf
or if you want bigger type use 1040SR for Seniors,
https://www.irs.gov/pub/irs-prior/f1040s--2020.pdf
And 2020 Instructions
https://www.irs.gov/pub/irs-prior/i1040gi--2020.pdf
2020 Tax and EIC Tables
https://www.irs.gov/pub/irs-prior/i1040tt--2020.pdf
Sch 1 : https://www.irs.gov/pub/irs-prior/f1040s1--2020.pd
Sch 2 : https://www.irs.gov/pub/irs-prior/f1040s2--2020.pdf
Sch 3 : https://www.irs.gov/pub/irs-prior/f1040s3--2020.pdf
Then when you do file 2021 enter 0 for the 2020 AGI since you are filing 2020 late.
You have to print and mail prior year returns. When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return. Don’t forget state.
