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⚖️ Construction Lien Law Guide

Protect your right to payment. Learn mechanics lien deadlines, preliminary notice requirements, and lien waiver best practices — written by a CPA who's seen contractors lose hundreds of thousands to missed deadlines.

Quick Answer: California Mechanics Lien Deadline

90 days from completion of work — or 60/30 days if a Notice of Completion is filed.

  • General contractors: 60 days after NOC recorded
  • Subcontractors & suppliers: 30 days after NOC recorded
  • No NOC filed: 90 days from completion for everyone

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 secures payment for labor, materials, or services provided to improve that property.

Think of it as collateral for your work. If you're not paid, the lien gives you the right to force a sale of the property to recover what you're owed. It's one of the most powerful tools contractors have to protect their payment rights.

From a CPA's Perspective

I've seen contractors lose $500,000+ because they missed a lien deadline by a single day. Lien rights are "use it or lose it" — the deadlines are strict and courts rarely grant extensions. Treat these dates like tax deadlines.

Why Mechanics Liens Exist​

Construction is unique because contractors improve property they don't own. Without lien rights, an owner could refuse to pay after receiving the benefit of your work. Mechanics liens level the playing field by giving contractors security interest in the property itself.

Preliminary Notice Requirements​

Before you can file a mechanics lien, most states require you to serve a preliminary notice (also called a "prelim" or "pre-lien notice"). This document notifies the property owner and general contractor that you're working on the project and preserves your lien rights.

California Preliminary Notice Deadline

20 Days​

Send within 20 days of first furnishing labor or materials to preserve your full lien rights. Late prelims only protect work done in the 20 days before sending.

Who Must Send a Preliminary Notice?​

PartyRequired?
Subcontractors✅ Always required
Material suppliers✅ Always required
Equipment rental companies✅ Always required
General contractors❌ Not required (direct contract with owner)
Laborers✅ Required if employed by subcontractor

What to Include in a Preliminary Notice​

  • Project address and description
  • Owner's name and address
  • General contractor's name and address
  • Your company information
  • General description of work/materials
  • Estimated total price (if known)
Don't Wait Until There's a Problem

Send your preliminary notice on every project, not just when you sense trouble. By the time payment issues arise, your 20-day window may have closed.

Critical Deadlines & Timeline​

Here's the complete timeline for protecting your lien rights in California:

California Lien Timeline​

EventDeadline
Preliminary NoticeWithin 20 days of first furnishing
Notice of Completion recordedOwner has 15 days after completion
Mechanics Lien (with NOC)GC: 60 days / Sub: 30 days after NOC
Mechanics Lien (no NOC)90 days from completion
Foreclosure lawsuit90 days from recording lien

What Triggers "Completion"?​

  • Actual completion of all work
  • Cessation of work for 60 continuous days
  • Owner occupancy or use
  • Acceptance by owner

Who Can File a Lien?​

Anyone who provides labor, materials, equipment, or services that improve real property can file a mechanics lien:

  • General contractors
  • Subcontractors (any tier)
  • Material suppliers
  • Equipment rental companies
  • Laborers
  • Architects & engineers (in most states)
  • Landscapers
  • Site work contractors

Lien Waivers Explained​

A lien waiver is a document where a contractor, subcontractor, or supplier gives up their lien rights in exchange for payment. California has four statutory lien waiver forms — using the wrong one can cost you.

The Four California Lien Waivers​

TypeWhen to UseRisk Level
Conditional ProgressBefore receiving progress payment✅ Low risk
Unconditional ProgressAfter progress payment clears⚠️ Medium risk
Conditional FinalBefore receiving final payment✅ Low risk
Unconditional FinalAfter final payment clears🚨 High risk
Never Sign Unconditional Before Payment Clears

An unconditional lien waiver is effective immediately upon signing — even if the check bounces. Only sign unconditional waivers after funds have cleared your bank account.

Best Practices for Lien Waivers​

  1. Use the statutory form — California law specifies exact wording
  2. Conditional before payment — Always use conditional waivers until money clears
  3. Track what you've waived — Maintain a log of all waivers signed
  4. Check amounts carefully — Verify the waiver amount matches the payment
  5. Get waivers from your subs — Before you waive, ensure your subs have waived

Common Mistakes to Avoid​

1. Missing the Preliminary Notice Deadline​

The Fix: Send prelims on day one of every project, even before you start work.

2. Sending to the Wrong Address​

The Fix: Verify the property owner's address through county records, not just what the GC tells you.

3. Not Tracking Deadlines​

The Fix: Use a lien tracking system or calendar with reminders at 10, 5, and 2 days before each deadline.

4. Signing Unconditional Waivers Too Early​

The Fix: Never sign unconditional until funds have cleared. If pressured, offer a conditional waiver.

5. Not Filing Because "It'll Ruin the Relationship"​

The Fix: Filing a lien is a business decision, not personal. Unpaid invoices over 90 days rarely get paid without leverage.

Public Works & Payment Bonds​

On public works projects, you can't file a mechanics lien against government property. Instead, your payment is secured by a payment bond.

Stop Payment Notice​

For public works in California, use a Stop Payment Notice to claim against funds the public entity owes the general contractor.

Notice TypeDeadline
Preliminary Notice (20-day)Same as private works
Stop Payment Notice30 days after NOC (or 90 days if no NOC)
Payment Bond Notice (2nd tier)20 days from first furnishing (prelim serves this purpose)
Lawsuit on Stop Notice90 days after expiration of lien period
Lawsuit on Payment Bond6 months after stop notice period expires
Public Works: Dual Remedies

On public projects, you can pursue both a stop payment notice AND a payment bond claim simultaneously. Use both for maximum leverage. See our Stop Notices Guide and Payment Bonds Guide for detailed procedures.

Design Professional Liens​

Architects, engineers, and land surveyors have special lien rights under California Civil Code § 8302 — a design professional lien.

Key Differences from Mechanics Liens​

FeatureMechanics LienDesign Professional Lien
Who can fileContractors, subs, suppliersLicensed architects, engineers, land surveyors
When it attachesAfter work begins on-siteBefore construction starts (design phase)
Preliminary noticeRequired for subs/suppliersNot required
AmountLabor/materials furnishedFees for design services
PropertyImproved propertyProperty to be improved

Why This Matters in Silicon Valley​

Tech campus projects, office build-outs, and data centers often have millions in design fees before a single shovel hits dirt. If an owner stops paying the architect or engineer during design, the design professional can lien the property even though no physical construction has started.

For GCs and Subs

If you're bidding on a project and discover a design professional lien on the property, that's a major red flag about the owner's payment practices. Check title before signing.

Tenant Improvement Liens & AB 2466​

The Silicon Valley Scenario​

Tenant improvements (TIs) are everywhere in Silicon Valley — tech companies building out leased office and lab space. The critical question has always been: can you lien the property if the tenant hired you, not the landlord?

California Law (as of 2025)​

AB 2466 (effective January 1, 2025) clarified mechanics lien rights on tenant improvement projects:

  • Tenant as "owner": When a tenant contracts for improvements to leased property, the tenant is treated as the "owner" for mechanics lien purposes
  • Lien attaches to leasehold: Your lien attaches to the tenant's leasehold interest, NOT the landlord's fee interest (unless the landlord consented to or required the improvements)
  • Landlord consent matters: If the landlord required or consented to the improvements as a condition of the lease, the lien MAY attach to the landlord's interest as well
  • Preliminary notice: Must still be served within 20 days — identify both the tenant and landlord/property owner
Critical for TI Work

Always send your preliminary notice to both the tenant AND the property owner/landlord. Even if your contract is only with the tenant, serving the landlord preserves your ability to argue the lien attaches to the fee interest if the landlord consented to or required the improvements.

Practical Tips for TI Projects​

  1. Get the lease (or relevant excerpts) — Look for clauses about tenant's right to improve
  2. Identify the landlord — County records, not just what the tenant tells you
  3. Check for landlord consent language — Does the lease require improvements?
  4. Serve prelim on everyone — Tenant, landlord, GC, lender
  5. Document the chain — Who hired you, who authorized the work

Prompt Payment Laws​

California has strong prompt payment protections that are separate from lien rights. Know these — they give you additional leverage.

Private Works (Civil Code §§ 8800-8814)​

RequirementRule
Owner to GCPay within 30 days of demand or per contract
GC to SubPay within 7 days of receiving payment from owner
Retention release (GC to Sub)Within 7 days of owner paying GC retention
Penalty for late payment2% per month on wrongfully withheld amounts
Disputed amountsMust pay undisputed portion on time

Public Works (Public Contract Code §§ 10262, 10853, 7107)​

RequirementRule
Agency to GCPay within 30 days of approved pay app
GC to SubPay within 10 days of receiving payment
Retention releaseWithin 60 days of project acceptance
Penalty for late retention2% per month
Penalty for late progress paymentInterest at 10% per annum
CPA's Take on Prompt Payment

I've seen subs owed $200K+ in retention that was held 6+ months after their work was accepted. At 2% per month, that's $4,000/month in penalties the GC owes you. Don't leave money on the table — send a formal demand letter citing Civil Code § 8812 (private) or Public Contract Code § 7107 (public).

No-Lien Clauses Are Void in California​

Some contracts — especially on large commercial projects — include clauses attempting to waive your lien rights. In California, these are void and unenforceable.

What the Law Says​

Civil Code § 8120: "An owner, direct contractor, or subcontractor may not waive rights under this part." Any contract provision requiring you to waive lien rights as a condition of getting the job is unenforceable.

What's NOT Void​

  • Lien waivers exchanged for payment — The four statutory waiver forms are valid
  • Arbitration clauses — You can be required to arbitrate a lien dispute
  • No-damage-for-delay clauses — Separate issue from lien rights
Don't Be Intimidated

If a GC or owner tells you "sign this no-lien clause or you don't get the job," you can sign it and still lien the property. The clause is void as a matter of law. However, it's better to push back and have it removed to avoid the argument entirely.

Silicon Valley County Resources​

County Recorder Offices​

For recording mechanics liens, notices of completion, and other documents:

CountyAddressPhoneOnline
Santa Clara70 W. Hedding St., East Wing, San Jose, CA 95110(408) 299-5688clerkrecorder.sccgov.org
San Mateo555 County Center, Redwood City, CA 94063(650) 363-4500smcacre.org
Alameda1106 Madison St., Oakland, CA 94607(510) 272-6362acgov.org/recorder
Santa Cruz701 Ocean St., Room 230, Santa Cruz, CA 95060(831) 454-2800sccoclerk.com
San Francisco1 Dr. Carlton B. Goodlett Pl., Room 190, SF, CA 94102(415) 554-4950sfassessor.org/recorder

Recording Tips for Silicon Valley​

  • E-recording available in Santa Clara, San Mateo, and Alameda counties through approved vendors
  • Recording fees: Typically $15 first page + $3 each additional page, plus any county surcharges
  • Title search: Use the county assessor's office or a title company to verify the correct legal description and APN before filing your lien
  • Processing time: Allow 5-10 business days for recording to appear in county records

Tools & Resources​

Calculators​

Use our Lien Deadline Calculator to automatically calculate your deadlines based on project dates.

Generators​

This guide is for educational purposes. For specific legal advice, consult a construction attorney licensed in your state.

Last updated: February 2026