A certificate of insurance (COI) is typically a one page document that provides policy details on your insurance coverages, verifying that you have the business insurance you claim to have. It summarizes essential information like the types and limits of coverage, the issuing insurance company or companies, your policy numbers, insurance limits, the named insured, and the policy or policies effective and expiration dates.  A certificate of insurance provides proof of insurance coverages that are in place at the time the certificate is produced.