California preliminary notice: the complete guide

If you’re a subcontractor or supplier in California, the preliminary notice is the single most important document for protecting your right to get paid. It’s a short notice you serve early in a project that preserves your ability to record a mechanics lienlater if the money doesn’t come. This guide covers what it is, who has to send it, the deadline, and how to serve it correctly.

What is a preliminary notice and why does it matter?

A preliminary notice (sometimes called a “20-day notice”) tells the owner, general contractor, and construction lender that you’re furnishing labor or materials and may have lien rights. Under Cal. Civ. Code §§ 8200–8216, serving it is a prerequisite to enforcing a mechanics lien for almost everyone who doesn’t contract directly with the owner. Skip it, and a perfectly valid invoice can become legally uncollectible through a lien.

Who has to send a preliminary notice?

Generally, you must serve one if you don’t have a direct contract with the property owner:

• Subcontractors and sub-subcontractors
• Material suppliers and equipment lessors
• The direct (general) contractor — but only on the construction lender, if a lender exists

Laborers who are paid wages are exempt. When in doubt, serve one anyway — it’s cheap insurance compared with losing lien rights.

What is the deadline to serve it?

Twenty days from the date you first furnish labor or materials to the job (Cal. Civ. Code § 8204). The clock starts on your first day on site or first delivery — not the contract date. If you serve late, the notice only reaches back 20 days before the service date, so any earlier work is unprotected. Use the preliminary notice deadline calculator to find your exact date.

Who do I serve, and how?

Serve the owner or reputed owner, the direct contractor, and the construction lender if there is one (Cal. Civ. Code § 8200). The accepted methods are certified or registered first-class mail with return receipt, or personal delivery (§§ 8110–8118). Keep the certified-mail receipts and a signed proof of service — that documentation is what makes the notice enforceable. See how to serve a preliminary notice for the step-by-step.

What happens after the preliminary notice?

Serving the notice keeps your options open. If you still aren’t paid, you can send a notice of intent to lien as a demand, then record a mechanics lien within the statutory window — 90 days from completion, or as little as 30 days if a Notice of Completion is recorded. Track those dates carefully; they’re unforgiving.

This page is general information, not legal advice, and does not create an attorney–client relationship. California lien and notice deadlines are strict and fact-specific — “completion” alone can be triggered by actual completion, the owner’s occupancy or use, or a 60-day cessation of labor. Notice Harbor is not a law firm. Confirm any deadline that matters to your claim with a licensed California construction attorney.