What Is a Certificate of Insurance (COI)? A Plain-English Guide
A certificate of insurance — usually an ACORD 25 form — is one page that proves coverage exists. Learn what it shows, what it doesn't, and how to read one before an event or a job.
How a Certificate of Insurance Works
Renting a space or working a job site? Here’s how you go from “I need insurance” to the venue, landlord, or general contractor holding proof of your general liability coverage — often the same day.
You Apply
A contractor, vendor, or anyone renting a space answers a few questions about the work or event.
Coverage Is Bound
A general liability policy is issued in your business name — often within minutes.
COI Is Generated
You provide the certificate holder's full name and address, and a certificate of insurance is created showing your coverage, limits, and dates.
Certificate Holder Gets Proof
The COI is delivered to the venue, landlord, or general contractor — naming them as additional insured if required. You're cleared to book the space or start the job.
The short version
A certificate of insurance (COI)is a single page that proves an insurance policy is in force. Venues ask renters for one. General contractors ask subcontractors for one. Clients ask vendors for one. It exists so you don't have to read someone's entire policy to confirm they're covered.
What a certificate shows
- The insured — the business or person who holds the policy.
- The carrier — the insurance company providing coverage.
- Coverage types — e.g. general liability, auto, workers' comp.
- Limits — the maximum the policy will pay (e.g. $1M / $2M).
- Effective and expiration dates — the window the policy is active.
- The certificate holder — the party receiving proof.
- Additional insured / endorsements — whether coverage extends to others.
The ACORD 25 — the standard certificate form
Most certificates of insurance are the same form: the ACORD 25, titled “Certificate of Liability Insurance.” ACORD is a nonprofit that writes the standardized insurance forms used across the US, and form 25 is what an agent fills out to prove general liability, auto, umbrella, and workers' compensation coverage on one page. When a venue or general contractor says “send me your COI,” they almost always mean an ACORD 25.
Because the form is standardized, the boxes sit in the same place every time — carrier, policy numbers, limits, effective dates, the certificate holder, and the description box where additional-insured wording goes. Anyone who reviews certificates can read one on sight, whichever agency issued it.
A few other ACORD forms cover what the 25 leaves out:
- ACORD 27 and ACORD 28 — evidence of property insurance, used for buildings and often required by lenders.
- ACORD 24 — certificate of property insurance.
- ACORD 23 — vehicle or vessel certificate.
For liability — the coverage an event host, renter, or subcontractor is asked to carry — the ACORD 25 is the form you'll hand over.
What a certificate does not do
A certificate is evidence only. It does not change the policy, guarantee coverage for a specific claim, or — on its own — protect the person holding it. For that, you need to be named as an additional insured, not just a certificate holder.
How to read one before an event or job
- Are the dates current and do they cover your event/job window?
- Do the limits meet your minimum requirement?
- Are you listed — as certificate holder and additional insured?
- Is the right coverage type present (e.g. general liability)?
Frequently asked questions
What is a certificate of insurance?
A certificate of insurance (COI) is a one-page summary issued by an insurer or agent that shows a policy exists, who is covered, the coverage types, the limits, and the effective dates. It is proof of coverage, not the policy itself.
Who issues a certificate of insurance?
The insurance carrier or the policyholder's licensed agent issues the certificate. The person or business who needs proof (a venue, a general contractor, a client) is listed as the certificate holder.
Is a certificate of insurance the same as being insured?
No. A certificate proves someone else has coverage. To actually be protected under that policy, you must be named as an additional insured — a separate step from being a certificate holder.
How do I verify a certificate of insurance is valid?
Check the effective and expiration dates, confirm the limits meet your requirement, verify your name and additional-insured status appear, and — if in doubt — contact the issuing agent listed on the form.
What is an ACORD 25 form?
The ACORD 25, titled “Certificate of Liability Insurance,” is the standard one-page form agents use to prove general liability, auto, umbrella, and workers’ compensation coverage. When someone asks for a certificate of insurance, they usually mean an ACORD 25.
Are there other certificate of insurance forms besides the ACORD 25?
Yes. The ACORD 25 covers liability. Property coverage uses the ACORD 27 or 28 (evidence of property insurance) or the ACORD 24 (certificate of property insurance), and vehicles or vessels use the ACORD 23. For the liability coverage a venue or contractor asks for, the ACORD 25 is standard.
Want certificates to arrive automatically instead of chasing them? Venues and contractors can set up a custom insurance link.