(a) In general. The interest rate established under 26 U.S.C. 6621(a)(2) shall be:

(1) On amounts outstanding before July 1, 1975, 6 percent per annum.

(2) On amounts outstanding:

(3) On amounts outstanding after December 31, 1982, the adjusted rates for overpayment and underpayment established by the Commissioner of Internal Revenue under 26 U.S.C. 6621. These adjusted rates shall be published by the Commissioner in a Revenue Ruling. See §70.94 of this part for application of daily compounding in determining interest accruing after December 31, 1982. Because interest accruing after December 31, 1982, accrues at the prescribed rate per annum compounded daily, the effective annual percentage rate of interest will exceed the prescribed rate of interest.

(b) Applicability of interest rates—

(1) Computation. Interest and additions to tax on any amount outstanding on a specific day shall be computed at the annual rate applicable on such day.

(2) Additions to tax. Additions to tax under any section of the Internal Revenue Code that refers to the annual rate established under 26 U.S.C. 6621, shall be computed at the same rate per annum as the interest rate set forth under paragraph (a) of this section.

(3) Interest. Interest provided for under any section of the Internal Revenue Code that refers to the annual rate established under this section, including 26 U.S.C. 6332(d)(1), 6343(c), 6601(a), 6602, 6611(a), 7426(g), and 28 U.S.C. 1961(c)(1) or 2411, shall be computed at the rate per annum set forth under paragraph (a) of this section.

[T.D. ATF-301, 55 FR 47614, Nov. 14, 1990]