20 Pa.C.S. § 7707: Governing law - UTC 107.

The meaning and effect of the terms of a trust shall be determined by:

(1) the law of the jurisdiction designated in the terms of the trust, but the mandatory rules of section 7705(b) (relating to trust controls; mandatory rules - UTC 105) shall govern if different from the law of the designated jurisdiction; or

(2) in the absence of an effective designation in the terms of the trust, the law of the jurisdiction in which the settlor is domiciled when the trust becomes irrevocable.