Certificate of Insurance (COI)

A Certificate of Insurance (COI) is a standardized summary — usually the ACORD 25 form — that a business's insurer or broker issues to prove active coverage. It lists the insured, the insurer, policy numbers, coverage types, limits, and effective and expiration dates.

A COI is proof, not the policy itself. It shows coverage existed when issued, which is why expiration dates and re-collection matter: a certificate from last year tells you nothing about coverage today.

Businesses request COIs from vendors and subcontractors before allowing work, so that if something goes wrong the vendor's insurance — not theirs — responds.