Why is a certificate of insurance required?

The COI demand usually arrives as an ultimatum — no certificate, no site access, no signed lease, no vendor number in the payment system. To respond well, understand what the other side is actually doing. They aren’t collecting documents; they’re enforcing a risk transfer they wrote into the contract, and the certificate is the cheapest available check that the transfer is real.

What the requirement is really doing

Everyone who hires you has their own insurance, their own deductibles, and their own loss history that sets their renewal pricing. If your work injures someone or damages property and you’re uninsured, the claim doesn’t evaporate — it migrates to the deepest insured pocket nearby: the landlord whose premises you worked on, the general contractor who brought you onto the job, the client who put you in front of their customers. Their insurer pays, their loss history worsens, and their insurer then pursues whoever caused the loss — you, personally.

Requiring insurance of every vendor, tenant, and subcontractor reverses that flow: your policy defends and pays for claims arising from your work. The COI is the verification step. As IRMI defines it, a certificate is “a document providing evidence that certain general types of insurance coverages and limits have been purchased” — evidence, and only evidence.

What they’re checking for

A counterparty reviewing your certificate is reading four things:

1. Limits. Most leases and small-commercial vendor agreements ask for $1M per occurrence in general liability; larger counterparties layer umbrella requirements on top. The number comes from their risk manager’s view of what a bad claim costs, not yours.
2. Additional insured status. The demand behind the demand: being named an additional insured gives your counterparty rights under your policy — including defense — for claims arising from your work. A certificate holder gets none of that; the distinction has its own page on our sister site.
3. Policy dates. Coverage lapses mid-contract are common enough that sophisticated requesters re-collect certificates at every renewal.
4. The right lines. A lease checks GL; a consulting MSA checks E&O; a hauling contract checks auto. The certificate shows whether the policy type matches the exposure they’re worried about.

It’s not only landlords and GCs

The same mechanism runs the rest of the economy’s plumbing. Regulators condition licenses on filed certificates — Illinois, for one, requires commercial pesticide applicators to file a certificate of liability insurance with the state at licensing and every renewal. Marketplaces and platforms impose insurance mandates on sellers (Amazon’s requirements are the best-known). Event venues demand COIs from caterers, photographers, and exhibitors. Any time someone lets your risk onto their premises, license, or platform, expect the paper.

Why the paper alone satisfies no one

Here’s the part both sides get wrong, in both directions. The certificate confers no rights and amends no policy — so a requester who collects a COI but never requires the additional insured endorsement has verified coverage exists without acquiring any right to it. Merchants asking insurance forums what a vendor COI even does are discovering this in real time. On your side of the table, the flip side is leverage: agreeing to “provide a COI” costs you nothing, but agreeing to endorsement changes — additional insureds, waivers — changes your actual policy. Read the insurance clause, not just the certificate request, before signing. And if your landlord’s requirements are the trigger, the negotiation dynamics are covered in can a landlord require business insurance.

Questions people actually ask

When is a certificate of insurance required? Whenever a contract makes it a condition: leases, construction subcontracts, vendor onboarding, venue agreements, platform seller terms, and some state licenses.

When do I need a certificate of insurance from a vendor? Whenever someone else’s work happens on your premises or under your name — the sidewalk-shoveling contractor is the canonical example. If they’re uninsured, their claims become yours.

Why get a certificate of insurance if no one asked? You don’t — the COI is proof for counterparties, not coverage. What you keep for yourself is the policy.

Do you need a certificate of insurance to be insured? No. The policy insures you; the certificate merely proves it to someone else, and it’s issued free by your insurer or agent when requested.

Sources are linked below. Where a requirement varies by state, we say so and link the regulator rather than generalizing from one state’s rule.