What is a Mechanics Lien?

A mechanics lien (also called a construction lien or materialman's lien) is a legal claim against a property that ensures contractors, subcontractors, and suppliers get paid for the work or materials they've provided. If you've worked on a property and haven't been paid, a mechanics lien attaches to the property title — making it very difficult for the owner to sell or refinance until the lien is resolved.

Why it's powerful

Unlike a standard invoice dispute, a mechanics lien affects the property itself — not just the GC or owner's cash account. Owners and lenders take liens seriously because a property with a lien on its title can't be sold or refinanced cleanly. This gives subcontractors real leverage to get paid even when they're at the bottom of the payment chain.

Who can file a lien

In California, any contractor, subcontractor, material supplier, equipment lessor, or laborer who contributes to a work of improvement on real property can file a mechanics lien — as long as they've followed the required preliminary notice procedures. Missing the preliminary notice deadline can eliminate your lien rights entirely.

The lien process overview

Lien vs. bond claim

On public projects (schools, government buildings), you can't file a lien against public property. Instead, you file a claim against the contractor's payment bond. The process is different but the goal is the same — getting paid for work you've performed.

Mechanics lien laws are complex and deadline-driven. This article is for general educational purposes only. Consult a California construction attorney before filing or responding to a lien.