Certificate of Insurance (COI): What It Is, What's On It

Turned Away at the Job Site

A plumber shows up to a commercial job site ready to start a three-week project. The general contractor's site manager meets him at the gate and asks for the Certificate of Insurance. The plumber pulls up the PDF on his phone — and the site manager points to the expiration date. The policy lapsed two weeks ago. He's told to leave and not come back until he has a current COI.

That scenario is more common than it should be. A COI is one of the simplest documents in contractor insurance — but the gap between "I have a certificate" and "I have current coverage with the endorsements the contract actually demands" is where contractors lose jobs, lose time, and lose money every week. The certificate isn't the policy. It's a snapshot of the policy at the moment the certificate was issued — and if the policy isn't right, the certificate doesn't make it right.

What's on a COI

A Certificate of Insurance is a one-page summary of your insurance coverage, issued on a standardized form called an ACORD 25. Its only purpose is to prove to a third party that an active insurance policy exists. It lists policy types, coverage limits, effective and expiration dates, and named insureds. It is not the policy itself — there's a disclaimer printed on the form that says exactly that. The COI is informational; the policy is the contract.

Every ACORD 25 contains the same fields, laid out in the same format. The grid below maps each field and what it represents.

Think of it like a driver's license. The license proves authorization to drive; it's not the law that grants the right to drive. Similarly, the COI proves a policy exists; it's not the insurance contract itself. The downstream consequence: any field on the certificate that misrepresents the underlying policy is a problem that surfaces at audit, at compliance check, or at the claim — long after the certificate was issued.

What Each Customer Type Demands

Almost everyone a contractor works for will require a COI before work starts. What they require on it varies by customer type. The table below maps demand profiles by who's asking.

General contractors and government customers are the most demanding — and for good reason. If your work causes damage or injury on their job site, they need to know your insurance will respond before theirs does. That's why they require not just proof of insurance, but specific endorsements like additional insured status and waiver of subrogation. Commercial landlords have similar requirements — if you're doing work on leased property, the landlord's lessors risk insurance policy often requires COIs from every contractor on site.

On the Certificate vs. On the Policy

The additional insured endorsement is the most requested — and most misunderstood — part of the COI process. When a GC asks to be listed as an additional insured on your policy, they're asking for your insurance to extend coverage to them for claims arising from your work. That extension only exists if the underlying policy actually has the endorsement on it. A name typed on the certificate doesn't create the endorsement; it just notes that the endorsement should be there.

For deeper detail on the rejection patterns this gap produces, see why your COI keeps getting rejected. For the speed conversation — and why same-day binding is the gap most rejected COIs come from — see why speed without review costs you jobs. The Contractor COI Checklist covers the endorsement language every commercial GC contract typically demands.

FAQ

Does a COI mean I'm actually covered, or just that I had coverage on the date it was issued?

The COI represents coverage at the moment it was issued. If the policy lapses, cancels, or gets restructured after the certificate goes out, the certificate doesn't update itself. That's why GCs check certificates against carrier records at compliance time — they want to verify the policy is still in force, not just that a certificate was issued at some point in the past.

What's the difference between an additional insured and a certificate holder?

Certificate holder means the GC receives a copy of the certificate and gets notified if the policy cancels. Additional insured means the GC is actually covered under your policy for claims arising from your work — your policy extends to defend and indemnify them. Certificate holder is informational. Additional insured is real coverage. Commercial GCs typically want both.

How long is a COI valid for?

The certificate is valid until the policy expiration date shown on it, or until the policy is cancelled — whichever comes first. Most commercial policies run 12 months, so most COIs are valid for 12 months from the effective date. If the policy renews, the GC typically asks for a new certificate reflecting the new effective and expiration dates.

What does CG 20 10 mean and why do GCs ask for it?

CG 20 10 is the ISO standard endorsement form that adds a third party as an additional insured for ongoing operations under a commercial general liability policy. CG 20 37 is the companion endorsement for completed operations. GCs ask for these specific form numbers because they want to verify the actual endorsement is attached to the policy — not just typed onto the certificate. The form number is the evidence; the typed name on the certificate is just the reflection.

The Bottom Line

A Certificate of Insurance is one page of paperwork. The policy behind it is what actually pays a claim. Most COI problems aren't about what's on the certificate — they're about what's not on the policy. The fix is reading the contract before binding and making sure the policy form actually carries the endorsements the certificate references.

If your certificates keep getting kicked back even when coverage is in force, the diagnosis lives at why your COI keeps getting rejected. For the speed side — and why same-day binding without contract review is the gap most rejected COIs come from — see why speed without review costs you jobs. State-specific requirements are at our state commercial insurance guides.

The fastest way to find out where your current setup stands? Use our contractor insurance risk calculator, then we'll review the contract, confirm the endorsements are actually on the policy, and walk through the gaps before the next COI request lands.