Mechanic's Liens in Pennsylvania

Pennsylvania's Mechanic's Lien Law gives contractors, subcontractors, and suppliers a powerful tool: the right to place a lien directly on the property where they performed work or supplied materials, even without a contract with the owner. The lien encumbers the real estate itself, making it difficult for the owner to sell or refinance until the lien is resolved.

Who Can File a Mechanic's Lien?

• General contractors : Can file a lien for any unpaid work, provided they had a contract with the owner.
• Subcontractors : Can file a lien even though their contract is with the general contractor, not the owner. But the subcontractor must give the owner a formal written notice of intention to file a claim at least 30 days before filing the lien claim (49 P.S. § 1501(b.1)). This is the single most important requirement subcontractors miss.
• Suppliers : Material suppliers may have lien rights, but only for materials actually incorporated into the improvement.

The Residential Property Exception

For residential properties, the Mechanic's Lien Law and related statutes provide important homeowner protections that do not apply to commercial projects:

• Defense of payment (§ 1301(b)). A subcontractor loses lien rights on this ground only if all three of these are true: the owner or tenant paid the contractor the full contract price; the property is or is intended to be the residence of the owner or the owner's tenant; and the property is a single townhouse or a building of one or two dwelling units. That is narrower than the Act's general definition of residential property, so a larger owner-occupied building does not qualify. This automatic protection does not exist on commercial projects.
• Waiver of liens (§§ 1401, 1402). On residential property of three stories or less, a contractor or subcontractor may waive lien rights by written instrument (§ 1401). The owner and contractor can also agree by stipulation filed with the Prothonotary that no liens may be filed, which is binding on subcontractors with proper notice (§ 1402).
• Written contract requirement (73 P.S. § 517.7(a)). Separately, the Home Improvement Consumer Protection Act (HICPA) requires a written contract for all home improvement work exceeding $500. A contract that fails to comply is not valid or enforceable against an owner (§ 517.7(a)). Even so, the Pennsylvania Supreme Court has held that § 517.7(g) does not bar a noncompliant contractor from recovering in quantum meruit. Shafer Electric & Construction v. Mantia , 96 A.3d 989 (Pa. 2014). The right to file a lien on an implied contract comes from a separate source. The Mechanics' Lien Law defines a "Contractor" as one who works "by contract with the owner, express or implied." 49 P.S. § 1201(4). Whether a contractor whose written contract is unenforceable against the owner under HICPA can support a lien on that implied contract is a separate and unsettled question. Shafer did not decide it: the trial court there struck the lien, and the Supreme Court ruled only on the quantum meruit claim.

For homeowners hiring contractors: these protections are significant but not absolute. Insist on a written contract, verify HICPA registration, and remember that paying your general contractor in full defeats subcontractor liens only if your property is a single townhouse or a building of one or two dwelling units.

Filing Deadlines: These Are Strict

Mechanic's lien claims must be filed within 6 months from completion of the work, which the Act defines as performance of the last of the labor or delivery of the last of the materials required by the terms of the claimant's contract or agreement, whichever last occurs (49 P.S. § 1201(8)). Work the contract did not require does not push that date back. This is a hard deadline; miss it by one day and the lien right is lost. The claim must be filed with the Prothonotary of the Court of Common Pleas in the county where the property is located.

After filing, the claimant must serve a copy of the claim on the property owner within one month of filing. The claimant must also commence an action to enforce the lien within 2 years of filing the claim, or the lien expires.

Defending Against a Mechanic's Lien

Property owners who receive a mechanic's lien have several options:

• Preliminary objections : Challenge the lien on procedural grounds: was the notice given? Was the claim timely? Is there a valid contract (express or implied) supporting the claim?
• Bond-off the lien: Under 49 P.S. § 1510, the owner may discharge the lien by depositing cash equal to the claim with the court, or by entering approved security in lieu of cash. The statute sets that security at double the required deposit, though the court may approve a lesser amount, never less than the full claim. This removes the lien from the property and transfers it to the deposit or security, allowing a sale or refinance to proceed while the dispute is resolved.
• Negotiate a settlement: Many lien disputes involve legitimate disagreements about scope, quality, or change orders. A negotiated resolution is often the most cost-effective outcome.
• Strike the lien: If the lien is procedurally defective, the owner can petition to strike it. Common defects include failure to give proper notice, late filing, insufficient description of work, or lack of any contractual basis (express or implied) for the claim. In Terra Firma Builders, LLC v. King, 249 A.3d 976 (Pa. 2021), the Pennsylvania Supreme Court held that an unperfected lien (one lacking the required affidavit of service under 49 P.S. § 1502(a)(2)) can be stricken at any time, even after trial. More recently, in PW Campbell Contracting Co. v. Yetter, No. 910 WDA 2024, 2025 WL 1099644 (Pa. Super. Apr. 14, 2025) (non-precedential), the Superior Court held that a "cost-plus" contract does not qualify as an "agreed sum" under § 1503(5), requiring the contractor to provide detailed itemization of labor and materials or risk having the lien stricken. Read more about mechanic's lien defenses.

Legal and factual content on this page was last verified: Aug. 2026. If you are reading this significantly after that date, confirm key provisions with current statute text or contact our office.