53 Pa. Stat. § 16981
In all cases in which a claim for taxes or other municipal claim shall have been or may hereafter be filed against any lot or piece of ground, whether improved or unimproved, by the city of Philadelphia, and it shall appear by affidavit of claimant or defendant, or other proper evidence, that said lot in fact consists of two or more lots belonging to different persons, the proper court shall permit and require the claim, whether before or after any partial payment thereof, to be so awarded and apportioned, that a due proportion thereof and no more shall be charged against and recovered from the several lots included in the claim as originally filed; and upon the payment of any part of a claim so apportioned, the court may direct a satisfaction pro tanto of such claim be entered of record by the city solicitor: Provided, That nothing herein contained shall in any way affect or impair the validity of any such claim upon the remainder of such lot or lots.
53 P.S. § 16981