@Yelloweggbasket
before you go through that trouble, let's revisit:
what happened in 2019 / 2020 doesn't matter. (I think what you are saying is that in 2019/ 2020 your income exceeded $160,000 so you don't beleive you were eligible for the stimulus)
what matters is 1) the number of people listed on your 2021 tax return Times $1400 LESS what you received in March-May, 2021
Are you saying that there is $2800 on Line 30 and the IRS reduced that by $1500? That suggests either a) you indeed received $1500 in March - May, 2021 or b) your 2021AGI is between $150,000 and $160,000 (but TT should have automatically figured this out, so less likely)
suggestions:
1) go back and check your March - May, 2021 bank account statements to see if there is a deposit for $1500. (that also suggests your 2020 or 2019 AGI was between $150,000 and $160,000)
2) check your transcript on IRS.GOV and see if there is a credit for $1500 - that may give you a clue on when the phanton deposit occured. Or if there is no $1500 phanton deposit, the issue is elsewhere (and I am totally off base)
3) if a deposit is listed, then you'll need to complete and mail in this tracer form
https://www.irs.gov/pub/irs-pdf/f3911.pdf
I would just hate for you to send in all the paperwork and then find out in 6-12 months (when the backlogged IRS finally reads it) that you need to follow a different tackt / process.
what do you mean they changed your filing status????????
