An Act amending the act of March 4, 1971 (P.L.6, No.2), known as the Tax Reform Code of 1971, in personal income tax, further providing for refund or credit of overpayment and providing for interest on refund or credit of overpayments; in general provisions, providing for interest on taxes due the Commonwealth and for interest on overpayments; and making repeals.

HB 959 amends Pennsylvania's tax code to require the state to pay interest on overpaid personal income taxes. It specifies that interest on refunds will accrue at the same rate used by the U.S. Treasury for federal taxes, starting from the date the overpayment was received. Taxpayers who overpay their state income tax - such as those who paid too much through estimated installments or filed early returns - will now receive interest on the excess amount. The bill also clarifies that no interest applies if a refund is issued within 60 days of the tax return deadline.