A COI (Certificate of Insurance) is a summary document - one page, standardized, produced by an insurance agent to communicate the existence and basic terms of a policy. The insurance policy is the actual legal contract between the insured and the carrier that governs what is and isn't covered, under what conditions, and for how much.
The difference is material. Relying on a COI when you need the policy is like relying on a book summary when you're being deposed on the contents. The summary might be accurate. It might not. Either way, the actual document controls.
What a COI Is (and Isn't)
COI vs Insurance Policy
A COI - typically the ACORD 25 form - shows: named insured, carrier, policy number, coverage types, limits, and policy dates. It also has checkbox fields for endorsements like additional insured and waiver of subrogation.
Here's what every ACORD 25 says in its own fine print: "This certificate is issued as a matter of information only and confers no rights upon the certificate holder. This certificate does not affirmatively or negatively amend, extend, or alter the coverage afforded by the policies below."
That disclaimer is doing serious legal work. The COI cannot create coverage that doesn't exist in the policy. It cannot confirm coverage terms that the policy doesn't contain. It is evidence that a policy exists - nothing more.
What the Policy Is
The policy is the contract. It contains:
- The declarations page (similar to the COI, but part of the actual policy)
- Coverage forms defining what is and isn't covered
- Exclusions - specific situations, activities, or damages that are not covered
- Conditions - requirements the insured must meet for coverage to apply
- Endorsements - modifications to the base policy, either adding or removing coverage
The endorsements are particularly important for third-party compliance purposes. When your contract requires your vendor to name you as an additional insured, that requirement is satisfied by an endorsement on the policy - a specific form attached to the policy document, not a checkbox on a COI.
Why You Can't Rely on a COI Alone
Endorsements. The additional insured checkbox on an ACORD 25 confirms that an additional insured endorsement was requested or may exist. It doesn't confirm which AI endorsement form was used, whether it covers completed operations, or whether the endorsement language matches what your contract requires. For high-stakes contracts, you should request copies of the actual endorsement forms.
Exclusions. A vendor's general liability policy may exclude the specific type of work you're hiring them to do. The COI will show GL coverage with a compliant limit. The exclusion won't appear anywhere on the COI. Only reading the policy or asking the agent directly will surface it.
Policy changes mid-term. After a COI is issued, the underlying policy can be modified. Coverage can be reduced, exclusions can be added, endorsements can be removed. The COI you received in January may not accurately reflect the policy in July.
Cancellation. Policies can be cancelled mid-term. Most policies require notification to certificate holders when a policy is cancelled - but that notification can lag, and it doesn't happen instantly.
When to Request the Actual Policy
For most vendor relationships, a properly verified COI is sufficient. But request the actual policy (or at minimum, the declarations page and relevant endorsements) when:
- The contract involves high dollar value or high liability exposure
- The vendor will be performing work with significant injury or damage potential
- You have reason to believe the COI may not reflect actual coverage
- Your contract requires specific endorsement language that you need to verify verbatim
- A claim is pending or you need to understand how the policy would respond
Your contract can require vendors to provide copies of policies and endorsements. Many risk managers include this as a standard term for high-risk vendor categories.
The Endorsement Connection
Endorsements are where the COI and policy most commonly diverge. Here's a common scenario:
Your contract requires the vendor to name you as additional insured using CG 20 10 (ongoing operations) and CG 20 37 (completed operations) endorsement forms. The vendor's agent checks the additional insured box on the ACORD 25. You accept the COI.
What you may not know: the vendor's policy has a blanket additional insured endorsement that covers ongoing operations only. There is no CG 20 37. If a claim arises from completed work, you are not covered - despite the checked box.
This is a real gap, and it happens regularly. Verifying endorsements means checking the actual endorsement forms, not the checkbox.
Common Scenarios Where the COI and Policy Diverge
- A vendor's COI shows a $2M aggregate limit. The policy actually has a per-project aggregate cap of $500K.
- The COI shows commercial auto coverage. The policy excludes owned vehicles used for the type of work you hired them to do.
- The COI notes a waiver of subrogation. The waiver endorsement on the policy only applies to scheduled projects, and your project isn't listed.
- The COI shows professional liability. The policy has a claims-made form with a retroactive date that doesn't cover prior work.
For a detailed breakdown of how to read every field on the ACORD 25, see the Certificate of Insurance guide.
Bramble compares COI data against your contract requirements automatically and flags discrepancies before they become claims. See how it works.