If a client, landlord, or general contractor has ever asked you for a certificate of insurance, you may have wondered what they actually want and what you are agreeing to. A certificate of insurance, or COI, is one of the most common documents in commercial relationships, yet it is also one of the most misunderstood. This article explains what a COI does, what related terms like additional insured and waiver of subrogation generally mean, and how to handle requests from both directions.
A certificate of insurance is a summary document that shows a policy exists. It typically lists the named insured, the types of coverage in force, policy limits, and effective dates, and it is usually issued by an agent or broker on a standardized industry form.
The key point is that a COI is proof of coverage, not coverage itself. It does not change, extend, or guarantee the underlying policy, and the actual policy language always controls what is and isn't covered. A certificate is essentially a snapshot in time, which is why parties often want it reissued or updated periodically.
Two terms frequently appear alongside COI requests. Additional insured generally means another party is added to your policy so that they may have certain protections under it, often in connection with work you perform for them. This status is created by an endorsement to the actual policy, not by the certificate itself.
A waiver of subrogation generally means your insurer agrees not to pursue recovery from a specific other party after paying a claim. Like additional insured status, it is typically added by endorsement and may affect your premium. Because both involve real contract terms, it is wise to review requests with your agent before agreeing.
General contractors, landlords, and clients commonly request certificates to confirm that you carry insurance before they let you work on a project, lease space, or sign a contract. The goal is generally to reduce the chance that a loss involving your business becomes their financial problem.
These requests are routine and usually tied to language in a contract or lease. Reading that language carefully matters, because it may specify minimum limits, additional insured status, or other endorsements you will need to arrange in advance.
The same logic runs in reverse. If you hire subcontractors or vendors, collecting current certificates from them helps document that they carry their own coverage rather than relying entirely on yours.
Many businesses keep a simple system for requesting, filing, and tracking these certificates so that expired ones are caught before work begins.
A frequent error is treating the certificate as if it were the policy. Because the COI does not alter coverage, assuming you are an additional insured without the supporting endorsement can leave a gap you only discover at claim time.
Other common issues include accepting expired certificates, overlooking required limits, and failing to verify that requested endorsements were actually added. When in doubt, your agent can help confirm that what the certificate shows lines up with the underlying policy.
Not by itself. It shows a policy exists, but the actual policy terms determine what is covered, so it is best to confirm details with your agent.
Generally no. Additional insured status is typically created by an endorsement to the underlying policy, and the certificate only reflects that it was arranged.
Many businesses request them at the start of each relationship and again at each renewal or when a certificate is set to expire, though your needs may vary.
These guides are a starting point — your business is unique. Talk to an advisor who can look at your actual exposures and structure coverage around them.