I had a owner finance mortgage in 2020, I sold the house 10-1-2020 I did not get a 1098, what do I do

[fanfare]

Schedule A line 8b is where you report interest you paid on a seller-financed mortgage.

[Carl]

Enter "as if" you received a 1098. I would expect you have some sort of paperwork that would show your outstanding balance on the loan as of Jan 1, 2020. If not, you should be able to "work it back" mathamatically and figure it. So long as it's below $750K then all the interest paid on that loan in 2020 up to and including the interest paid with the payoff amount, will be deductible as a SCH A itemized deduction.