In case it helps anyone else who has left things to the last minute:
I attempted to e-file my Federal and State married-filing-jointly return on 14 October 2022.
- Federal failed (rejection code IND 031-04) - wrong 2020 AGI or signed with wrong pin.
- State failed due to Federal failing.
I had filed 2020 return quite late (~Dec 2021) by mail. The federal return was accepted by IRS ~July 2021. I ensured that 2020 federal return was indeed accepted using the IRS lookup. I also downloaded the 2020 federal transcript to confirm the 2020 AGI I was using was correct - it was. Nevertheless, for the my second attempt at filing 2021 returns, I followed the suggestion mentioned a few times in this thread, to use $0 as AGI. Since I was filing jointly there was only one box to enter 2020 AGI. I entered $0. The returns were accepted (within around 1 hour).
