What is a COI? Certificate of Insurance Explained

Last updated: July 9, 2026

A certificate of insurance is a one-page document that summarizes the key details of an insurance policy. It shows who is insured, what coverages are in place, what the limits are, and when the policies expire.

It's not a policy. It doesn't confer coverage. It's evidence that coverage exists at the time it was issued.

What's on a certificate of insurance

The standard form is the ACORD 25. Most COIs you'll encounter follow this format. Key fields include the name of the insured, the insurance producer, the types of coverage, policy numbers, effective and expiration dates, coverage limits, and the certificate holder.

The certificate holder is the organization requesting the COI — a general contractor, a property manager, a city, or any other party that needs proof of coverage before allowing a vendor or subcontractor to work.

What a COI doesn't tell you

This is where most compliance processes fall short.

A COI confirms that a policy existed when the certificate was issued. It doesn't confirm that the policy was endorsed to name you as an additional insured. It doesn't confirm that the wording meets your contract requirements. It doesn't confirm that the umbrella follows form. It doesn't confirm that the policy hasn't been cancelled since the certificate was printed.

Those details live in the endorsements. Three endorsement types come up in almost every vendor and subcontractor contract: additional insured status, which gives you direct standing on the vendor's policy; primary and non-contributory language, which controls how that policy responds relative to yours; and waiver of subrogation, which prevents the vendor's carrier from coming after you after paying a claim. Each requires a separate endorsement document, requested and reviewed independently from the COI.

Why organizations require COIs

Any organization that hires outside vendors, subcontractors, or tenants carries exposure if those parties cause injury or damage and don't have adequate insurance. Requiring a COI before work begins is the baseline step in transferring that risk.

Construction companies require COIs from subcontractors before they start on a job site. Property managers require them from tenants and vendors. Public agencies require them from every contractor they hire. Airports require them from every company operating on the airfield.

The requirement is simple. The execution is where things get complicated.

Why COI tracking is harder than it looks

Most organizations are managing COIs from dozens, hundreds, or even thousands of vendors at any given time. Policies expire. Endorsements change. Vendors resubmit the wrong documents. Someone on the team approves a COI without checking the endorsements. A subcontractor starts work before their renewal comes through.

Each of those gaps is a potential liability exposure. And most of them don't surface until there's a claim.

Manual tracking — spreadsheets, email chains, shared drives — works at low volume. It breaks down fast as vendor counts grow and requirements get more complex.

How PINS helps

PINS automates COI collection, tracks expirations, and uses AI to review submitted documents against your requirements. It flags gaps in coverage, missing endorsements, and wording that doesn't match what your contract requires — before work starts, not after a claim.

Your team stays in control of every approval, waiver, and exception. PINS handles the tracking and the document review so you don't have to.

If you're managing more than a handful of vendors and doing it manually, it's worth seeing what automated COI tracking looks like in practice.

FAQ answers

What is a certificate of insurance?

A certificate of insurance is a one-page document that summarizes the key details of an insurance policy. It shows who is insured, what coverages are in place, what the limits are, and when the policies expire. It is not the policy itself and does not confer coverage. It is evidence that coverage existed at the time the certificate was issued.

What is the difference between a COI and an endorsement?

A certificate of insurance is a summary document that shows what coverage exists. An endorsement is a separate document that modifies the policy itself. A COI can show that a vendor carries general liability insurance, but only the endorsement confirms that your organization is named as an additional insured, that coverage is primary and non-contributory, or that subrogation rights have been waived. The certificate tells you coverage exists. The endorsement tells you whether that coverage actually protects you.

Why is a COI not enough to prove insurance compliance?

A COI confirms that a policy existed when the certificate was issued. It does not confirm that the policy was endorsed to meet your contract requirements, that coverage has not been cancelled since the certificate was printed, or that endorsement language matches what your contract specifies. Compliance programs that stop at the certificate miss the endorsement verification that determines whether coverage will actually respond when a claim occurs.

What is an ACORD 25?

The ACORD 25 is the standard form used for certificates of insurance in the United States. Most COIs you encounter follow this format. It includes fields for the insured's name, the insurance producer, types of coverage, policy numbers, effective and expiration dates, coverage limits, and the certificate holder. The ACORD 25 also includes checkboxes for additional insured status and waiver of subrogation, but a checked box only confirms the notation was requested. The endorsement on the policy is the only confirmation those protections exist.