I had to amend my 2020 taxes and now have taxes due. I would like to pay online rather than send a check with the 1040X to avoid additional interest. With the current backlog at the IRS it could be many months before they process my amended return.
Do I pay only the amount shown on the 1040X, or do I use some online calculator to estimate the interest and penalties and pay those immediately online also? I found a post that said the IRS will bill me for the interest and penalties, but how will that interest be calculated? Up to the day I paid the amount due online, or include the months it takes them to process my amended return? Do I need to include a note with my 1040X stating that I paid online or include an online receipt?
The instructions say to pay by check. My fear is they do not process the check or the return for another 6-9 months and I will owe even more in interest. How are check payments handled?
In short, I want to pay taxes due asap and stop any more accruing interest and penalties. What is the best way to do that? Thanks!
