Certificate of insurance
A one-page document, issued directly by a contractor's insurer, that proves their liability and workers' compensation coverage is current — your evidence they're actually insured.
A certificate of insurance (COI) is the proof behind a contractor's claim that they're 'licensed, bonded, and insured.' It lists the policy types, coverage limits, and expiration dates for the contractor's general liability insurance (which pays if their work damages your home) and workers' compensation (which keeps you from being sued if a worker is hurt on your property). Never take a verbal assurance: ask for the COI to be sent to you *directly by the insurance agency*, not handed over as a photocopy that could be expired or forged, and confirm the dates cover your whole project. Verifying the COI is a core step in [finding and vetting a good contractor](/guides/how-to-find-and-vet-a-contractor).