Definition
What is Certificate of insurance (COI)?
A certificate of insurance is a one-page summary (often an ACORD 25 form) showing that a contractor or vendor had certain policies in force on the date it was issued. It is evidence that a policy exists, not proof of what the policy actually covers.
What it means in practice
A COI lists insurers, policy numbers, coverage types, limits, and effective dates. The standard ACORD form states on its face that it is “issued as a matter of information only,” “confers no rights upon the certificate holder,” and “does not affirmatively or negatively amend, extend or alter the coverage.” In other words, the certificate itself grants nothing — the underlying policy and its endorsements control.
Two common traps: the certificate may not prove the board and building were actually added as additional insured (that requires the endorsement, not the certificate line), and the cancellation language may promise no enforceable notice if coverage lapses. A certificate on file is not the same as coverage.
Key points for boards
- A COI summarizes coverage as of its issue date; it is not the policy.
- Verify additional-insured status on the endorsement, not the certificate.
- Read the cancellation clause — “endeavor to mail” or “in accordance with policy provisions” may mean no guaranteed notice.
- Confirm the certificate is current and covers the full scope and term of the work.