What a COI Actually Does
A certificate of insurance is proof that your coverage exists, issued to a general contractor, owner, or agency who requires it before you work or get paid. The certificate itself is simple. What trips contractors up is the specific endorsements the contract demands: additional insured status, waiver of subrogation, and primary and non-contributory wording. Miss one and your invoice sits until it is fixed.
Why It Holds Up Payment
COI requirements are written into your contract, and the party paying you checks them against the certificate you provide. A mismatch, an expired policy, or a missing endorsement is one of the most common reasons a contractor payment gets delayed. Getting the wording right up front is faster than fixing it after the fact.