"Failure to pay tax reported on return: Internal Revenue Code §6651(a)(2)
- 0.5% of tax not paid by due date, April 15; 0.25% during approved installment agreement (if return was filed on time, and taxpayer is an individual); 1% if tax is not paid within 10 days of a notice of intent to levy
- Recurring charge on the remaining unpaid tax each month or part of a month following the due date, until the tax is fully paid or until 25% is reached
- Full monthly charge applies, even if the tax is paid before the month ends"
This is simple interest, not compound interest.
