61 Pa. Code § 31.45
A credit shall be granted with respect to vehicles purchased for use outside of this Commonwealth equal to the tax paid to another state by reason of a tax similar to the tax imposed by the Commonwealth. Credit may not be granted unless the other state grants similar tax relief to persons who have paid tax to the Commonwealth. A listing of other states granting similar tax relief may be obtained from the Department of Revenue (Attn: Legal Bureau) upon request.
61 Pa. Code § 31.45
This section cited in 61 Pa. Code § 31.7 (relating to use tax); 61 Pa. Code § 31.41 (relating to definitions); 61 Pa. Code § 31.41a (relating to scope); 61 Pa. Code § 33.2 (relating to purchase price); and 61 Pa. Code § 60.16 (relating to Local Sales, Use and Hotel Occupancy Tax).