noun · also: COI
certificate of insurance
In plain English
A one-page summary of your insurance coverage, issued to a third party as proof you're insured.
A landlord, GC, or vendor will usually ask for one before letting you start work. It's evidence of coverage, not the policy itself — the actual coverage is in the policy and endorsements.
What it covers
The certificate names the insured, the carriers, the policy numbers, the limits, and the certificate holder requesting it. Often issued as ACORD 25 (liability) or ACORD 27/28 (property).
What it does not cover
It does NOT add coverage or modify the policy. The fine print on the form says exactly that. To actually add a party as insured, you need an endorsement attached.
Where it trips people up
A certificate showing 'additional insured' is meaningless without the endorsement to back it up. Always ask for the endorsement form (CG 20 10 etc.), not just the cert.
The technical version
A document evidencing the existence of insurance coverage, issued by an insurer or its representative to a third party with an interest in the insured's operations.