Certificate of insurance (COI)
A one-page summary of a contractor's insurance at the moment it was issued. In construction it is almost always the ACORD 25, the Certificate of Liability Insurance.
ACORD 25On the certificate
Policy types, policy numbers, policy dates and limits, the producer (the broker who issued it), the insured and the certificate holder. A description box carries notes such as project names and additional insured wording.
What to check
That every coverage your project requires is listed, the limits meet the requirement, the dates run through the work, and the insured name matches the contract.
The common gap
Treating the certificate as the coverage. The ACORD 25 says it is issued as a matter of information only and confers no rights on the certificate holder. Rights come from the policy and its endorsements.
Go deeper on forsured.ai: A COI on file isn't proof of coverage
Related: Additional insured · Notice of cancellation · Try Spot the Gap
General information, not legal or insurance advice. Ask your broker what your policies actually carry.