Effective January 1, 2020 to December 31, 2020, the rate of interest on underpayments of Pennsylvania taxes will be 5% per annum. Additionally, the rate of interest on overpayments of tax will be 3% per annum (except for personal income tax overpayments, which accrue interest at the same rate as for underpayments). See Interest Rate Notice, Pa. Dept. Rev., PA. Bull. Doc. No. 19-1949, Pa. Bull. Vol. 49, No. 52, 12/28/19. For perspective purposes, the interest rates for 2019 were 6% for underpayments and 4% for overpayments.
For any questions related to interest calculations or just Pennsylvania state and local tax questions in general, please contact Paul Morcom at 717-237-5364 or Sharon Paxton at 717-237-5393.