What is a certificate of insurance?

What a certificate of insurance actually is

A certificate of insurance (COI) is a short document, usually one page, issued by an insurance agent or broker that summarises the policies a business currently carries. In North America most of them are printed on the ACORD 25 form, so once you learn to read one you can read all of them.

It is a summary, not the policy itself. The form exists so a general contractor, a property manager, or a lender can see at a glance who is insured, by whom, for how much, and until when. It is not a contract, it does not create coverage, and the form itself says it does not amend, extend, or alter the policies it describes.

That distinction sounds pedantic until a claim lands. What protects you is the underlying policy and the endorsements attached to it. The certificate is the signpost pointing at them — so the job of the person collecting COIs is to confirm the signpost matches what your subcontract requires.

What's on a COI, field by field

• Named insured — the business the policy covers. Check it matches the company you actually signed the subcontract with, not a trade name or a parent company.
• Insurance carriers — who stands behind each policy. A certificate with no carrier named, or a carrier you cannot look up, is worth questioning.
• Policy periods — the start and end date of every policy listed. This is the field that quietly expires on you.
• Coverage types and limits — typically general liability (per occurrence and general aggregate), commercial auto, workers' compensation with employer's liability limits, and sometimes umbrella or excess coverage.
• Description of operations — what work the coverage is for, and often the specific project or address.
• Certificate holder — who received the certificate. This is usually your company.
• Additional insured and waiver of subrogation — either ticked in the boxes or written into the additional remarks. These are the two that decide whether a claim stays on your subcontractor's policy.
• Cancellation notice — how many days' notice the carrier gives before ending a policy early. Common values are 10 or 30 days; many contracts require it.

What a COI cannot tell you

A certificate is a snapshot someone typed up, and it can be wrong in ways that only surface during a claim.

It does not prove a policy is still in force. A certificate printed last month can describe a policy that has since been cancelled for non-payment.

It does not amend coverage. If the remarks say 'additional insured' but no endorsement was ever issued, there is nothing behind the sentence.

It does not show your contract's requirements. Your subcontract may demand $2M general liability and a waiver of subrogation; the certificate only reports what the sub's policy actually says.

It does not tell you whether the limits apply per occurrence or in aggregate across the whole policy year — a $1M aggregate can already be partly used up.

The three checks that matter before a sub mobilizes

1. 1Do the limits match the contract? Compare the certificate line by line against the insurance clause in your subcontract — general liability, auto, workers' compensation, umbrella — and confirm the numbers are at or above what you agreed, not merely close.
2. 2Are you named correctly? Your company (and often the owner or the developer) should appear as additional insured for the project. A certificate that lists a previous project, a misspelled entity, or only names you as certificate holder is not compliant.
3. 3Do the dates cover the job? The policy period must run past your scheduled completion, not just past today's date. A sub whose coverage expires in six weeks is a renewal you have to chase now.

Why this lands on the general contractor

If an uninsured or underinsured subcontractor injures someone or damages property on your job, the claim rarely stops at their door. Owners look to the general contractor's policy first, because it is the one that is easy to find, and your carrier will spend months trying to recover the money back down the chain.

Current, correct certificates are how you keep that risk where the contract put it. They are also the first thing an owner's risk manager, a lender, or a surety asks to see — and being able to produce a clean, current roster in a few minutes says something about how the job is being run.

Where COI collection usually goes wrong

• The certificate arrives by email, gets opened once, and disappears into a thread nobody can find later.
• Requirements live in someone's head, so different projects ask different subs for different things.
• The expiry date is copied into a spreadsheet but never re-checked, so the file looks fine long after the policy lapsed.
• The sub's agent sends an updated certificate mid-project and it is never matched against the original.
• Nobody can say, at a moment's notice, which subs on a live job are currently compliant.

Frequently asked questions

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