Guide to Preliminary Notices

If you’re a contractor in California, you’ve likely stared down the barrel of a payment dispute, wondering if you should file for a lien, and if it would hold up in court. The Golden State’s lien laws are designed to protect laborers and suppliers—but one slip can cost you everything.

In California’s construction industry, subcontractors, suppliers, and other contributors face payment risks that can jeopardize project success. A preliminary notice, also called a “preliminary 20-day notice,” is a critical tool for securing payment rights and preserving the ability to file a mechanics lien. This notice, which is sent by Certified Mail, informs the Property Owners, General Contractors, and Lenders (Banks) of your role in a project, establishing a legal foundation for future claims if payments are delayed or withheld. This guide provides an overview of sending preliminary notices in California.

What Is a Preliminary Notice in California?

A preliminary notice is a formal document required under California Civil Code § 8000-9566. It notifies key project stakeholders—property owners, general contractors, and sometimes lenders—that you are providing labor, materials, or services to a construction project. The notice includes your business name and contact information, the project address, a description of the work or materials supplied, and an estimated payment amount. It’s not a lien but a mandatory step to preserve your right to file a mechanics lien later if payment issues arise. Without it, you may lose the ability to secure unpaid amounts against the property.

Why Send a Preliminary Notice?

In California, sending a preliminary notice is a legal prerequisite for most subcontractors and suppliers to maintain lien rights. It ensures transparency by alerting owners to downstream contributors, helping them track project funds and prevent payment disputes. Failing to send the notice within the required timeframe will stop you from filing a valid mechanics lien.

In addition, the notice signals professionalism and encourages timely payments by highlighting potential consequences for non-payment. For subcontractors managing multiple projects, adopting a routine for sending notices minimizes oversights and strengthens cash flow.

When to Send the Notice

California law mandates that preliminary notices be sent within 20 days of first furnishing labor, services, equipment, or materials to a project. If sent late, the notice only protects lien rights for work performed in the 20 days prior to delivery and onward. For maximum protection, send the notice as soon as you begin work or deliver materials. This is especially critical for fast-moving projects where deadlines can be missed. Timing applies to both private and public projects, though public works may involve additional notices, such as a stop payment notice.

How to Prepare and Send

FieldLatch makes it easy to send a preliminary notice using our website. If you don’t already have the information of the Property Owner, General Contractor and Lender, we can help retrieve it on your behalf.

By sending your preliminary notice early, you establish a legal foundation to file a mechanics lien if payments become an issue. This guide explores everything subcontractors need to know about sending preliminary notices, drawing from best practices to help manage projects effectively—much like streamlined apps that handle project tracking, forms, and compliance in one place.

California law provides contractors with an excellent system to help guarantee payment for your work. But it was one very important requirement: you must send a notice to the Property Owner, the Construction Lender (aka Bank) and the General Contractor. Failure to give this notice will invalidate your right to pursue a lien, in the case that you have not received payment.

In short:

What is a preliminary Notice?

It’s a letter which secures your right to getting paid and which must:

(1) be sent before a subcontractor starts a new job and
(2) must be sent by certified mail to.

How to send notice?

It must be sent by Certified Mail to every entity who will accept payment until it reaches you. For example, if you are a Subcontractor, the payment starts from the Lender (or Bank), then to the Property Owner, then to the General Contractor, then to the Subcontractor, and then to the Material Supplier.

By sending the preliminary notice at the start of each project, you will guarantee payment and will help your company succeed.

Final note

FieldLatch is NOT an attorney, and should not be considered a substitute for getting sound legal advice from a real attorney.