What is a certificate of insurance? A plain-English guide to the ACORD 25

Updated October 2026. Written for US construction and property firms.

If you hire subcontractors or vendors, you collect certificates of insurance. This guide explains what the document is, what it proves, and what it does not prove. It also walks through the ACORD 25 form box by box.

What is a certificate of insurance (COI)?

A certificate of insurance is a one-page document, usually on the ACORD 25 form, issued by an insurance agent or broker. It summarizes a policyholder's coverage: insurer names, policy numbers, coverage types, limits, and effective and expiration dates. It is proof that insurance exists, not the insurance itself.

What is ACORD 25?

ACORD 25 is the standardized Certificate of Liability Insurance form published by ACORD, the insurance industry's standards body. It is the near-universal format for COIs in the United States. It shows general liability, auto, umbrella, and workers' compensation coverage on one page.

Who issues a certificate of insurance?

The subcontractor's insurance agent, broker, or carrier issues it, not the subcontractor. A certificate that was typed up or edited by the sub themselves is a fraud red flag: always accept COIs only from the producer listed on the form.

How do I read an ACORD 25 certificate?

Read it from top to bottom. The top half names the agent, the insured business and the insurance companies. The middle grid lists each policy with its number, dates and limits. The bottom has a description box, the certificate holder and a cancellation notice. Check the dates and limits first.

1. Producer. The agent or broker who issued the certificate. Call this office, not the sub, if anything looks wrong.
2. Insured. The sub's business name and address. It should match the name on your subcontract.
3. Insurers A to F. The insurance companies behind each policy. Each one has a letter that the grid refers to.
4. Coverages grid. One block per policy type. General liability covers injuries and property damage the sub causes. Automobile liability covers their vehicles. Umbrella or excess liability adds extra limits on top. Workers' compensation covers the sub's injured employees.
5. ADDL INSD and SUBR WVD. Two narrow columns. A "Y" under ADDL INSD (additional insured) means someone was added to the policy. A "Y" under SUBR WVD means a waiver of subrogation applies. That is a promise by the insurer not to sue you to recover what it paid on a claim.
6. Policy effective and expiration dates. The start and end of each policy. These are the dates you track.
7. Limits. The maximum the policy pays. "Each occurrence" is the limit for one incident. "General aggregate" is the total for the whole policy year.
8. Description of operations. Free text. It often names the project and states additional insured status. On its own, this box does not create coverage.
9. Certificate holder. Your company, as the business that asked for the certificate.
10. Cancellation. A standard notice about what happens if a policy is cancelled. It does not oblige the insurer to tell you.

How long is a COI valid?

A COI has no validity period of its own. It is a snapshot that is only as current as the policy expiration dates printed on it. Most policies run 12 months, so most companies require a fresh certificate at every policy renewal and before each new project.

Is a COI the same as an insurance policy?

No. The certificate is informational only. It does not amend, extend, or alter the coverage of the policies listed, and the ACORD 25 form says so in its own disclaimer. Coverage rights come from the policy and its endorsements. Treat the certificate as a summary and the policy as the real thing.

What should I check on every certificate I receive?

Check that the insured name matches your contract and that no policy has expired. Make sure each required coverage is listed with limits at or above your minimums. Confirm your company appears as certificate holder. If your contract requires additional insured status or a waiver of subrogation, ask for the endorsements too.

• The certificate came from the producer, not typed up by the sub.
• Every coverage your contract requires is on it. See our subcontractor insurance requirements by trade.
• The limits meet your minimums.
• The dates cover the whole job, or you have a reminder set for the renewal.
• Your exact legal name is in the certificate holder box.

Can I accept an expired COI?

No. An expired certificate proves nothing about current coverage. Require an updated certificate showing the renewed policy term before the sub continues work. Ask the sub to have their agent send an updated certificate. Until it arrives, treat the sub as uninsured and keep them off the job site.

How do I keep track of certificates once I have them?

Log every policy with its expiration date in one place. Then request a renewal certificate about 30 days before each date. A spreadsheet with color rules works for a small number of subs. Software that reads the PDF and sends reminders automatically works better once you are chasing more than about 15.

Start with our free COI tracking spreadsheet. When it gets heavy, CoiPatrol is free for up to 10 subs and $49 a month for up to 50.