11 Pa.C.S. § 145A03
(b) Assessment effective.— An assessment made pursuant to this chapter shall become effective 30 days after personal notice is given by any of the following means:
(3) Posting notice at or upon the property after reasonable attempts to give personal notice pursuant to paragraphs (1) and (2) have failed.
Cross References. Section 145A03 is referred to in section 145A08 of this title.