Mechanics Lien California: What Homeowners Need to Know

You paid your general contractor every dollar you owe. The ADU is finished.

Then a framing subcontractor you’ve never met records a mechanics lien on your house — for $38,000 your GC never passed along. Under California Civil Code §8400, that sub has every right to do it.

Mechanics lien California law gives subcontractors, suppliers, and laborers a direct claim against your property for unpaid work — even if you already paid the person who hired them.

This is the risk most homeowners don’t learn about until it’s too late. This guide explains how construction liens work in California, when they’re valid, what the deadlines are, and how to protect yourself before one ever gets recorded.

A mechanics lien is a legal claim recorded against your property by someone who provided labor, materials, or equipment on a construction project and wasn’t paid. It’s governed by California Civil Code §§8000–9566. This is distinct from a tax lien or judgment lien — it’s specific to construction work under California lien law.

Who can file one:

Who	When They Can File
General contractor	Hired directly by the homeowner, not paid per contract
Subcontractor	Hired by the GC, not paid for their portion of work
Material supplier	Delivered lumber, concrete, fixtures — invoice unpaid
Equipment renter	Provided excavators, lifts, tools — rental unpaid
Laborer	Performed work on the project, wages unpaid

Once recorded, a construction lien in California clouds your property title. You cannot sell or refinance until it’s resolved — through payment, a court order, or a bond.

Yes. And so can every subcontractor and supplier they hired, even if you never knew those people existed. This is the part of California lien law that catches homeowners off guard.

Here’s how it plays out on an ADU project:

1. You hire a GC for a $250,000 ADU. You pay every invoice on time.
2. The GC hires a framing sub for $38,000. The sub finishes the work.
3. The GC doesn’t pay the sub.
4. The sub records a contractors lien on your property for $38,000.
5. You now owe $38,000 again — or face foreclosure proceedings.

California is effectively a “double payment” state. The homeowner can end up paying twice for the same work if the GC diverts funds. The CSLB warns homeowners directly about this risk.

One critical protection: unlicensed contractors cannot file a valid mechanics lien. Under Business & Professions Code §7031, unlicensed contractors are barred from bringing any action for compensation. This is one reason verifying a contractor’s CSLB license before signing matters.

Before anyone other than the direct contractor can file a mechanics lien, they must send you a 20-day preliminary notice. This is required under Civil Code §8200.

A preliminary notice in California is not a lien. It’s a heads-up. It tells you: “I’m providing labor or materials to your project, and if I don’t get paid, I have the right to file a lien later.”

Key facts about the pre lien notice in California:

• Must be sent within 20 days of when the sub or supplier starts providing labor or materials
• If sent late, they can only claim amounts from 20 days before the notice was sent forward
• The general contractor does not need to send one — they have a direct contract with you
• Receiving a preliminary lien notice is normal on any project with subcontractors

What to do if you receive one: don’t panic. File it. Cross-reference the sender against your contractor’s subcontractor list. If someone you’ve never heard of sends one, ask your GC immediately.

California mechanics lien requirements include strict deadlines. Miss them, and the lien right expires.

Action	Who	Deadline
Preliminary notice	Subs, suppliers	Within 20 days of starting work
Record lien (no Notice of Completion)	All claimants	Within 90 days of project completion
Record lien (Notice of Completion filed)	Direct contractor	Within 60 days of Notice of Completion
Record lien (Notice of Completion filed)	Subs, suppliers	Within 30 days of Notice of Completion
Foreclosure lawsuit	Lien claimant	Within 90 days of recording the lien
Lien expires (no lawsuit filed)	Automatic	90 days after recording

The Notice of Completion is your best tool here. Record one with your county recorder as soon as the project passes final inspection. It shrinks the lien window from 90 days to 30 days for subs and 60 days for the GC.

That compressed timeline works in your favor.

How long does a mechanics lien last in California? Ninety days after recording. If no foreclosure lawsuit is filed in that window, the lien expires automatically.

But it stays on your property record until formally released or removed by court order.

Verify Your Contractor’s License

A CSLB license check confirms the contractor is active, bonded, and carrying workers’ comp. Unlicensed contractors can’t file a valid lien — but they can still damage your property and leave you with no recourse. Verify any contractor’s license here before signing.

Request Lien Waivers With Every Payment

California has four statutory mechanics lien release forms under Civil Code §§8132–8138: conditional waiver on progress payment, unconditional waiver on progress payment, conditional waiver on final payment, and unconditional waiver on final payment.

At every milestone payment, request a conditional lien waiver from the GC and every subcontractor. When you make the final payment, get unconditional waivers from everyone. These contractor lien release forms are your receipt proving each party has been paid.

Track Every Preliminary Notice

Keep a file of every 20-day preliminary notice you receive. Cross-reference each one against your contractor’s subcontractor list. If a notice comes from someone your contractor didn’t mention, that’s an immediate conversation.

Record a Notice of Completion

File with your county recorder within 15 days of final inspection. This shortens the lien filing window from 90 days to 30/60 days. It’s a simple form and costs under $50 to file in most California counties.

Don’t Overpay Your Contractor

California’s contractor deposit law limits the first payment to $1,000 or 10% of the contract, whichever is less. After that, every payment should match completed work. Never pay ahead of progress — that’s the pattern behind every major ADU contractor collapse.

If a mechanics lien has already been recorded on your property, you have several options under California lien rights:

• Negotiate and pay. If the lien is valid and the amount is genuinely owed, the fastest resolution is negotiating a settlement and getting a signed lien release.
• Demand a lien release form. Once the underlying debt is paid, the claimant must provide a mechanics lien release form under Civil Code §8480.
• Petition the court. If the lien is invalid or frivolous, you can file a petition to release it. The claimant has 20 days to prove validity. A frivolous mechanics lien in California can result in the claimant paying your attorney fees.
• Post a lien release bond. A surety bond equal to 125% of the lien amount removes the lien from your property while the dispute is litigated.
• Wait 90 days. If no foreclosure lawsuit is filed within 90 days of recording, the lien expires. You can then petition for formal removal from the property record.

If the contractor who caused the lien problem is CSLB-licensed, file a CSLB complaint as well. Fund diversion — taking your money without paying subs — is a license violation.