Why does my certificate of insurance not count as an additional insured endorsement?

The ACORD 25 form disclaims its own authority in writing. The certificate cannot grant, extend, or amend coverage—only the endorsement attached to the policy can do that. A COI is a receipt, not the transaction.

Does the COI vs endorsement distinction vary by state?

The core rule does not. The ACORD 25 and the CG 20 10 / CG 20 37 endorsements are standard national forms, so a certificate describes and an endorsement grants wherever you work. State laws on certificate misuse, and on how far an additional insured clause can reach, do vary.

Why do general contractors reject a bare ACORD 25 certificate?

A bare COI is often rejected by compliance portals because GCs need the endorsement schedule and primary and non-contributory language attached. A COI alone provides no actual coverage protection.

An ACORD 25 is the standardized Certificate of Liability Insurance form published by ACORD. It summarizes a policy's carrier, policy numbers, limits, and effective dates. Its own header states it is issued 'as a matter of information only' and 'confers no rights upon the certificate holder,' meaning it describes coverage but does not grant or amend it.

Is a COI legally binding?

No. A certificate of insurance is not a contract and generally cannot be enforced against the insurer to create coverage. The policy and its endorsements—such as the CG 20 10 or CG 20 37 additional insured endorsements—are the documents with legal effect. Courts have repeatedly held that a certificate holder cannot rely on the COI alone to establish additional insured status.

Does a COI make someone an additional insured?

No. Only an additional insured endorsement attached to the general liability policy (commonly CG 20 10 for ongoing operations and CG 20 37 for completed operations) makes a third party an additional insured. A COI may reference that such an endorsement exists, but the endorsement pages themselves carry the legal weight.

Certificate of Insurance vs Additional Insured Endorsement

Q: What is the difference between a COI and an additional insured endorsement?

A certificate of insurance (COI) is a one-page ACORD 25 form that describes coverage but confers no rights—it states 'for information only.' An additional insured endorsement (CG 20 10 or CG 20 37) is a form attached to your general liability policy that actually amends coverage and names the GC as an insured. Only the endorsement has legal effect.

Q: What are CG 20 10 and CG 20 37 endorsements?

CG 20 10 is the additional insured endorsement for ongoing operations, and CG 20 37 covers completed operations (the coverage that survives after you leave the site). These are the two forms a general contractor almost always requires.

Certificate of insurance vs endorsement: COI grants zero rights while CG 20 10/37 endorsements provide actual coverage. Learn the critical difference.

This content is general information only and is not legal, tax, financial or insurance advice. Speak to an appropriately licensed professional before acting on it.

Your certificate of insurance (COI) does not count as an additional insured endorsement because a COI is a summary snapshot, not a contract. The COI is issued "for information only" and, per its own printed language, confers no rights and amends no policy. The additional insured endorsement (typically a CG 20 10 for ongoing work and a CG 20 37 for completed operations) is the actual policy form that grants the GC coverage. A GC that wants proof of additional insured status, not just a COI, is asking for the endorsement pages, and the legal weight lives in those pages, not in the certificate.

Last updated: October 2026.

TL;DR

A COI is issued on an ACORD 25 form that states in its own header it is "for information only" and grants zero rights — it is not the coverage.
The additional insured endorsement (CG 20 10, CG 20 37) is the endorsement form attached to your general liability policy that actually names the GC as an additional insured.
A GC withholding payment "pending a COI" usually means they also need the endorsement schedule and the primary and non-contributory language attached — a bare ACORD 25 is often rejected by compliance portals.
The distinction comes from standard national forms (ACORD 25, ISO CG 20 10 and CG 20 37), so it works the same way wherever you work; state rules on certificate misuse vary.

What is the difference between a COI and an additional insured endorsement?

The difference is that a certificate of insurance describes coverage and an endorsement changes coverage. Only one of those actually protects the general contractor.

A certificate of insurance (COI) is the one-page ACORD 25 your broker emails you. It lists your carrier, your policy numbers, your limits, and your dates. Read the box at the top: it says the certificate is issued "as a matter of information only" and "confers no rights upon the certificate holder." That sentence is why a COI, by itself, does not make anyone an additional insured. It is a receipt, not the transaction.

An additional insured endorsement is a form attached to your general liability policy that amends who counts as an insured. The two forms a GC almost always wants are the CG 20 10 (additional insured for ongoing operations) and the CG 20 37 (additional insured for completed operations, the coverage that survives after you leave the site). When those forms name the GC or list "any person or organization you are required by written contract to add," the GC actually has coverage under your policy. That is the document with legal effect.

Definition — Additional insured endorsement: A policy form (commonly CG 20 10 for ongoing work and CG 20 37 for completed operations) that extends your general liability coverage to a third party such as a general contractor. Unlike a COI, the endorsement is part of the contract of insurance and can be enforced against your carrier. The COI merely reports that such an endorsement may exist; the endorsement pages themselves are what a court, a claims adjuster, and a compliance reviewer will actually read to determine coverage. If the endorsement is not attached to the policy, the third party is not covered — regardless of what the certificate says.

Why does the ACORD 25 carry no legal weight?

The ACORD 25 is a standardized industry form published by ACORD (the Association for Cooperative Operations Research and Development). Its disclaimer language is deliberate: the certificate "does not affirmatively or negatively amend, extend or alter the coverage afforded by the policies." In plain terms, the form is designed to summarize, never to grant. Many states also have certificate-of-insurance laws that bar a certificate from being used to alter policy terms; your state insurance department can confirm the rule where you work.

The ISO/NCCI form families themselves define what each endorsement does. The CG 20 10 and CG 20 37 are ISO commercial general liability forms; their scope and edition dates matter, because an older CG 20 10 edition may exclude completed operations entirely. See the ISO commercial lines form catalog and the NCCI resource library for how these standardized forms and their edition dates are maintained and interpreted.

Courts have repeatedly reinforced the same hierarchy: the policy and its endorsements control, and a certificate cannot create coverage the policy does not provide. For a representative treatment of certificate-versus-endorsement enforceability, see the International Risk Management Institute (IRMI) analysis of certificates of insurance and additional insured status, which surveys the case law establishing that a COI holder generally cannot sue on the certificate itself.

Does the distinction change from state to state?

The core rule does not. The ACORD 25 is a national form and the CG 20 10 / CG 20 37 are national ISO forms, so the certificate describes and the endorsement grants wherever you work. What can vary is each state's statutory language on certificate misuse and penalties, and how far state law lets an additional insured or indemnity clause reach. IRMI's definition of a certificate of insurance explains the general rule.

What should you actually send the GC?

Send three things, not one:

The ACORD 25 (the summary they filed request against).
The additional insured endorsement pages (CG 20 10 and/or CG 20 37, correct edition dates), showing the GC named or covered by blanket wording.
Any primary and non-contributory and waiver of subrogation endorsements the contract requires.

A bare ACORD 25 is often rejected by compliance portals precisely because reviewers know it is "information only." The endorsement pages are the deliverable that ends the dispute.

Methodology: This guide is based on the published text of the ACORD 25 certificate form, the ISO CG 20 10 and CG 20 37 endorsement forms, state certificate-of-insurance laws, and secondary legal analysis from IRMI. Form scope depends on edition date; verify the specific edition attached to your policy before relying on it.