61 Pa. Code § 151.23
Tax credits which are applied in payment of a tax debit are credited as of the post-mark date of the payment from which the credit originated.
The provisions of this § 151.23 adopted March 23, 1979, effective March 24, 1979, 9 Pa.B. 1071.
This section cited in 61 Pa. Code § 151.21 (relating to definitions).