What is a preliminary notice (20-day notice) in California?

California's preliminary notice is mandated by Civil Code §8200-§8214 as a core element of the mechanic's lien system. Every sub, supplier, and lessor on a construction project (except the prime contractor) must serve a preliminary notice to preserve lien rights.

Who must send it:

• Subcontractors (electricians, plumbers, framers, etc.).
• Material suppliers (lumber yards, cabinet vendors, tile distributors).
• Equipment lessors.
• Design professionals in some cases.

Who does NOT send preliminary notice:

• The prime contractor who has a direct contract with the owner (they file a lien directly).
• Laborers claiming wages (separate lien rights).

When it must be sent:

• Within 20 days of first providing labor or materials.
• Late notices preserve lien rights only for work performed in the 20 days before notice.

What it must contain (per Civil Code §8202):

• Description of work or materials to be provided.
• Estimated total price.
• Name and address of the person providing.
• Name of the person who contracted for the work.
• Property description.
• Statement of lien rights.

How it must be sent:

• First-class mail with certificate of mailing, registered mail, or certified mail.
• Personal delivery with signed receipt.
• Served on: the owner, the prime contractor, and the construction lender.

Why homeowners should care:

• A preliminary notice is your earliest warning that a sub or supplier is owed money on your project.
• If your GC fails to pay that sub or supplier, they can file a mechanic's lien against your property — even if you paid your GC in full.
• Save every preliminary notice. Match them to lien waivers when your GC requests a draw.

Practical response to receiving a preliminary notice:

1. Save the notice.
2. Add the sub or supplier to your draw-release checklist.
3. Before releasing each draw to your GC, require an unconditional lien waiver from every noticed sub/supplier for work done to date.
4. If you don't receive a waiver, hold the draw until you do.

Related notices:

• Notice of Completion (Civil Code §8182) — filed after project completion; shortens lien-filing window.
• Notice of Cessation (Civil Code §8188) — filed if work stops for 60+ days.

AskBaily's LA-matched contractors include lien waiver collection from subs as a required part of the draw schedule. See /ask/what-is-a-mechanics-lien-release for the full waiver workflow.