What Is a Certificate of Insurance (COI)?

In insurance, COI means certificate of insurance: a document summarizing a business's reported insurance policies, limits, and dates. It is evidence to review, not a new insurance policy or a guarantee that a particular claim is covered.

If a customer asks your business for a COI, ask your insurance agent or insurer to issue one. If you hire vendors, collect their certificates and compare the reported information with your written requirements.

What does COI mean in business?

In a vendor-onboarding or insurance request, COI usually refers to the certificate of insurance. In other business contexts, the same initials can mean conflict of interest. Check the request: a document listing carriers and policy dates is an insurance certificate; a disclosure of personal or financial interests serves a different purpose.

How does a COI work?

Here is a fictional vendor-onboarding example:

1. A property manager gives a plumbing vendor the project's written insurance requirements and the certificate recipient's legal name and address.
2. The vendor asks its insurance producer for the certificate and any requested supporting endorsements.
3. The manager compares the submission with those requirements and asks the producer about missing or inconsistent information.
4. The manager records the review and schedules follow-up before the relevant policies expire.

Receiving the PDF completes the collection step. It does not, by itself, complete the review or transfer every risk to the vendor's insurer.

Who needs to collect certificates of insurance?

Anyone who lets another business work on their site, project, or property:

• General contractors collect COIs from every subcontractor before the sub sets foot on a job site.
• Property managers and HOAs collect them from landscapers, roofers, plumbers, cleaners — any vendor working on the property.
• Businesses of every kind collect them from the contractors who service their buildings and equipment.

Keep the certificate with your review notes and supporting documents so someone else can understand what was checked and which questions remain open.

What information is on a COI?

A standard ACORD 25 certificate shows:

Section	What it tells you
Producer	The insurance agency that issued the certificate
Insured	The business that holds the policies — this must match the vendor you hired
Insurers	The actual carriers (with NAIC numbers) backing each policy
Coverage lines	General liability, auto, umbrella, and workers' comp — each with policy numbers, effective and expiration dates, and dollar limits
Description of operations	Free-text section where endorsements like additional insured status are often noted
Certificate holder	You — the party the certificate was issued to

For a field-by-field walkthrough, see how to read an ACORD 25 form.

Is a COI the same as the insurance policy?

No — and this matters. A COI is issued as a summary for information only. It confers no coverage by itself, and the fine print says exactly that. Two practical consequences:

1. The certificate can be outdated the day after it's issued. If the vendor cancels the policy, your paper copy doesn't change.
2. Endorsements need checking. Being named an "additional insured" only works if a real endorsement (like form CG 20 10) is attached to the policy — a checked box on the certificate is a claim, not proof.

What should I check on a COI?

At minimum, five things:

1. The insured identifies your vendor — clarify differences in legal names or trade names with the producer.
2. Reported limits meet your written requirements — compare each required limit separately; see our subcontractor requirements guide.
3. Policy dates are current — and won't expire mid-project.
4. Required endorsements appear — additional insured, waiver of subrogation, primary & non-contributory wording.
5. Each required coverage line is addressed — ask about blank entries rather than assuming coverage or an exemption.

How much does a COI cost?

The certificate itself is typically issued without an additional charge when you already have an active policy. You pay for the underlying insurance; changes to coverage may affect that cost. Ask your agent what the request involves before assuming an invoice is for the certificate alone. Travelers explains certificate cost separately from policy cost.

Software for collecting and tracking other businesses' certificates is a third expense. If that is what you are budgeting for, see COI tracking software pricing.

Is the certificate holder the insured?

These are different roles. The insured is the business whose policies appear on the document. The certificate holder is the recipient. Being named as the recipient does not create additional insured status. See certificate holder vs. additional insured before treating a certificate addressed to you as evidence of coverage for your organization.

What is a COI number?

A certificate may have a certificate number or revision number used to identify the document. The coverage grid lists policy numbers for the individual policies. When asking about a discrepancy, send the certificate and identify the relevant policy row rather than assuming one document number identifies all the coverage.

How do people track COIs?

A practical record includes the vendor, policies, expiration dates, outstanding documents, and the person responsible for follow-up. A spreadsheet can support a small vendor list if someone maintains it. Our COI tracking spreadsheet guide describes that workflow.

Keep renewals and unresolved questions visible. A folder full of PDFs makes it difficult to see which vendor needs action today.

How do I review a COI quickly?

The free COI checker extracts reported information from a PDF or photo and compares it with your selected requirements. It can help organize document review; it does not verify policy authenticity or guarantee coverage. Ask the producer about discrepancies and obtain the supporting policy documents when needed.

ACORD's certificate FAQ explains why a certificate cannot change a policy. This guide is decision support, not insurance, legal, or coverage advice.