Note:

Any part of a month counts as a full month, i.e., a return with a due date of 4-15-2026 with a received date of 5-20-2026, without any extension or disaster dates, is two months late. See IRM 20.1.2.3.7.1, Period Subject to IRC 6651(a)(1), for more information on determining the months or period a return is late.

After calculating the penalty period, determine the amount subject to the FTF penalty. Determine unpaid tax ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ ≡ following RDD or disaster due date, whichever is later. This is the amount subject to penalty. The disaster due date for FTF is determined without regard to any extension of time to file. See IRM 20.1.2.3.7.2, Amount Subject to IRC 6651(a)(1), for more information on determining the amount subject to the penalty.

The base FTF penalty is calculated by multiplying the number of months the tax return is delinquent (up to five), times the amount subject to penalty, times 5%. The resulting FTF amount applies to cases without a Failure to Pay penalty. The formula for calculating the base FTF penalty is: Period X Amount X 5%.

The FTF penalty when Failure to Pay (FTP) also applies is calculated by subtracting the overlapping amount of FTP penalty from the base FTF amount. When FTP and FTF apply to the account, calculate the FTF penalty as follows:

Compute the base FTF penalty as outlined above.

Compute the FTP penalty for the same number of months subject to FTF penalty. For math error returns, calculate FTP using the lesser of the tax per taxpayer or the corrected tax amount. For more information see IRM 3.14.2.6.17.5, Failure to Pay Penalty Recomputation.

Subtract b) from a) to get the correct FTF amount when overlapping FTP also applies.