- 11 - that such failure is due to reasonable cause and not due to willful neglect. The amount of the addition is equal to 5 percent of the amount required to be shown as tax on the delinquent return for each month or fraction thereof during which the return remains delinquent, up to a maximum addition of 25 percent for returns more than 4 months delinquent. B. Section 6654 Section 6654 provides for an addition to tax in the event of an underpayment of a required installment of individual estimated tax. Sec. 6654(a) and (b). Each required installment is equal to 25 percent of the “required annual payment”, which, in turn, is equal to the lesser of (1) 90 percent of the tax shown on the individual’s return for that year or, if no return is filed, 90 percent of his or her tax for such year, or (2) if the individual filed a return for the immediately preceding taxable year, 100 percent of the tax shown on that return. Sec. 6654(d)(1)(A) and (B)(i) and (ii). The due dates of the required installments for a calendar taxable year are April 15, June 15, and September 15 of that year and January 15 of the following year. Sec. 6654(c)(2). An individual’s tax, for purposes of section 6654, consists of income and self-employment tax determined before the application of any wage withholding credits which, under section 6654(g)(1), are treated as payment of estimated tax. See sec. 6654(f). Section 6654(e) provides certain specified exceptionsPage: Previous 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 NextLast modified: November 10, 2007