Is a sub's certificate of insurance real and current? How California GCs can check

Short answer

A certificate of insurance (usually an ACORD 25) is evidence of coverage, not the policy. California law requires it to say it isn't an insurance policy and doesn't change the coverage.
Confirm it with the sub's insurance agent or broker. Get their phone number yourself, not from the PDF you were sent.
Match the named insured, the policy dates and the workers' comp details against the sub's CSLB license record.
If it looks fake, don't let the sub start, keep a copy, and you can report suspected insurance fraud to the California Department of Insurance.

What a certificate is, and what it isn't

A certificate of insurance is a document that shows certain types of coverage and limits have been bought (IRMI definition). Most subs send one on the ACORD 25 form. It's a summary that someone fills in. It isn't the policy.

California Insurance Code §384 requires a certificate to state that it isn't an insurance policy and doesn't change the coverage of the policies it lists. So a certificate can't give you coverage the policy doesn't have. It can only point you to the policy.

That's why the questions on this page matter. Is there a real policy behind the paper? Is it in force today? Will it still be in force when the sub finishes? The certificate of insurance checklist covers what the certificate should show. This guide covers how to tell whether it's real.

Warning signs on a certificate

The name doesn't match. The named insured is different from the business on the sub's CSLB license or your subcontract.
Odd dates. The policy period is longer or shorter than a normal term, the dates were changed, or the certificate date is after the work started.
No real producer. The agent or broker box is blank, has only a cell phone, or has a free email address.
Edits you can see. Fonts that don't line up, text pasted over other text, or a PDF that was clearly edited.
Only the sub will send it. If the sub won't let you get a certificate from their agent directly, that's worth a call.
It doesn't match CSLB. The workers' comp carrier or policy number on the certificate is different from what the CSLB record shows.

None of these proves a certificate is fake. Each one is a reason to confirm it before the sub starts.

How to confirm it: step by step

Find the agent or broker yourself. Take the agency name from the "Producer" box. Don't use the phone number printed there. Look the agency up with the California Department of Insurance. Its license lookup searches agents and brokers by name or license number and shows license status and discipline history. Then get a phone number from a source you trust, such as the agency's own website or the insurer's website.
Call and ask simple questions. Is this policy in force for this business? What are the policy dates? Did your office issue this certificate on this date? Ask them to email a fresh certificate to you directly, from their own address.
Ask for endorsements if your contract requires them. Additional insured status and waiver of subrogation come from endorsements, not the certificate. See additional insured for subs.
Match the named insured to the CSLB license. Look up the sub's license number on CSLB's Instant License Check or on Sub Check. The business name on the license, the certificate and your subcontract should be the same.
Compare the workers' comp details. The CSLB record shows the sub's workers' comp policy (carrier, policy number and dates) or an exemption. If the record shows an exemption and the certificate shows a comp policy, or the policy numbers don't match, ask why. See workers' comp and subs.
Check the dates against your schedule. The policies should run from the sub's first day to the last. If a policy ends mid-job, put the renewal date on your calendar now.
Write down what you did. Who you called, the number, the date and what they told you. Keep it with the certificate.

Keep it current

A certificate shows coverage on the day it was issued. A policy can be canceled after that, and the certificate won't change. Check again at three points: before the sub starts, when any policy on the certificate reaches its end date, and before your own workers' comp audit (see workers' comp audits and subs).

The CSLB record helps between calls. If a licensee doesn't keep required workers' comp, the license is suspended automatically (B&P §7125.2). A status change on the license is often the first sign a policy lapsed. See what to do if a sub's license is suspended mid-job.

If the certificate looks fake

Don't let the sub start, or stop the work they haven't done yet, until you have a certificate the agent confirms.
Keep everything. The PDF, the email it came in and your notes from the call.
Tell the sub in writing what didn't match, and ask for a certificate sent to you directly by their agent.
Report it if you think it's fraud. The California Department of Insurance takes reports of suspected insurance fraud from the public, online, and you can report anonymously (CDI fraud reporting).
Talk to your lawyer about your subcontract and any payments, and tell your own insurance agent so they know about the exposure.

Checklist

Agent found independentlyAgency license looked up with CDI, phone number from a source you chose.
Policy confirmed by phone or emailIn force, with dates, for this named insured.
Name matches the CSLB licenseSame business on the license, the certificate and your subcontract.
Workers' comp matches the CSLB recordSame carrier and policy number, or an exemption you've asked about.
Dates cover the jobRenewal dates on your calendar.
Notes savedWho you spoke with and the date.

Common questions

Is a certificate of insurance proof that a sub has coverage?

It's evidence, not proof. California Insurance Code §384 requires a certificate to state that it isn't an insurance policy and doesn't change the coverage of the policies it lists. Confirm it with the sub's agent or broker.

Why shouldn't I call the phone number on the certificate?

If a certificate was faked, the phone number on it may be faked too. Look the agency up with the California Department of Insurance and get its number from a source you choose, such as the agency's or insurer's own website.

What should match between the certificate and the CSLB record?

The business name, and the workers' comp details. The CSLB record shows the sub's workers' comp policy (carrier, policy number and dates) or an exemption. If they don't line up, ask before the sub starts.

How often should I check a sub's certificate?

Before the sub starts, when any policy on it reaches its end date, and before your own workers' comp audit. A certificate doesn't change if the policy is canceled later.

What do I do with a fake certificate?

Keep the sub off the job until a real certificate comes from their agent, save the PDF and emails, and talk to your lawyer. You can report suspected insurance fraud to the California Department of Insurance online, and you can do it anonymously.

General information for California contractors, current as of November 4, 2026. It isn't legal advice; rules change, so check the official source linked above.