Hi, I'm trying to match my software's calculation of my underpayment penalty with instructions for Form 2210 line 8. I know it's currently a draft, but the basic instructions say:
To figure your 2018 tax, first add the amounts listed in (1) later, then
subtract from that total amount the refundable credits listed in (2)
later that are shown on your 2018 tax return.
My software seems to be doing that, however it also seems to be adding in line 13 from the 2018 1040.
I can't find anywhere in the instructions where it says to add in line 13.
