A certificate of insurance (COI) is a one-page summary from an insurer confirming that a vendor or contractor carries active coverage — typically general liability, and often workers’ compensation — with the policy limits and dates listed. Landlords ask for a current COI before letting a contractor work on the property.
The point is to shift risk: if an uninsured worker is injured on your property or damages the building, you can end up exposed, whereas a properly insured vendor’s policy responds instead. Best practice is to collect a COI before the first job, confirm it hasn’t expired, and keep it on file. Vetting vendors for valid insurance is part of dispatching work safely.