Note:

FTP is generally computed on the lesser of the tax shown on the return (IRC 6651(a)(2) or on subsequently assessed tax (TC 290/300) that is not shown on the return (IRC 6651(a)(3).

Determine when the FTP penalty begins: (Note: All payments have a ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ after the RDD)

On the posting of an original return showing balance due , FTP begins on the payment due date (generally the return due date) and ends on the date the payment(s) is made.

On math error assessments, FTP begins on the twenty-second day (or the eleventh business day if the module balance is $100,000 or greater) after the 23C Date (the notice and demand date).

On adjustments to tax that cause a balance due, FTP begins on the twenty-second day (or the eleventh business day if the module balance is $100,000 or greater) after the 23C Date.