In construction, COI stands for certificate of insurance. It is a one-page document, usually an ACORD 25, that proves a contractor or subcontractor carries active insurance. It lists the insurer, the types of coverage, the limits, and the dates the coverage is in force. General contractors and project owners collect a COI from every trade before work starts, so a claim from the job lands on the contractor’s insurance instead of theirs.
Key Takeaways
- A COI summarizes coverage. It is not the policy and gives the certificate holder no rights under it.
- Ask every contractor and subcontractor for their own COI before they set foot on site.
- Most construction contracts require general liability, workers’ compensation, and auto coverage, with umbrella limits on larger jobs.
- Being the certificate holder only gets you a copy. Additional insured status, added by endorsement, is what actually protects you.
- A COI is a snapshot. Policies can lapse or be canceled mid-project, so verification and tracking matter as much as collection.
What Does COI Mean in Construction?
A COI means the same thing in construction as anywhere else: a certificate of insurance issued by the contractor’s insurance agent, broker, or carrier. It matters more on a job site because the work is riskier and more regulated, with many trades, heavy equipment, and hazardous work zones.
Contractors provide COIs to project owners, general contractors, property managers, and other hiring parties, often because the contract requires it. If an uninsured or underinsured contractor causes property damage or an injury, the cost can fall on the business that hired them. For the bigger picture, see our guide to what a certificate of insurance is.
What Is on a Construction COI?
A standard construction COI shows:
- The insurance company and the producer (agent or broker)
- The named insured, meaning the contractor
- Policy types and policy numbers
- Coverage limits for each policy
- Effective and expiration dates
- The certificate holder
- Additional insured status, waiver of subrogation, and other endorsements
- A description of operations, which often names the project or location
To see a filled-in form, look at our certificate of liability insurance form example.
What Coverage Should You Require From Contractors?
The right mix depends on the scope of work and the level of risk. These are the policies construction contracts ask for most often:
| Coverage | What it covers | When to require it |
|---|---|---|
| General liability | Third-party bodily injury and property damage caused by the contractor’s work | Every contractor and subcontractor on site |
| Workers’ compensation | Medical care and lost wages if the contractor’s employees are hurt on the job | Any contractor with employees. Most states require it by law |
| Commercial auto | Accidents involving vehicles used for the work | Contractors who deliver materials, run service trucks, or drive to and around the site |
| Umbrella or excess liability | Extra limits on top of general and auto liability | Higher-value contracts, higher-risk work, or crowded sites with many trades |
| Professional liability (E&O) | Financial harm from mistakes or negligence in design or professional services | Architects, engineers, and design-build contractors |
| Builder’s risk | The structure under construction, plus materials, fixtures, and equipment | Usually carried by the owner or general contractor for the project itself |
Set the minimum limits for each policy in your contract, then check every COI against them. Our guide to the general liability insurance certificate covers the most common one in more detail.
Additional Insured vs. Certificate Holder
These two roles appear on nearly every construction COI, and mixing them up is one of the most costly mistakes a general contractor can make.
- Certificate holder. The party that receives the COI as proof of coverage. Being listed gives you a copy, but no rights under the policy.
- Additional insured. A party added to the contractor’s policy by endorsement, commonly CG 20 10 for ongoing operations and CG 20 37 for completed operations. The endorsement is what extends the contractor’s coverage to protect you.
If you want the protection and not just the paperwork, require additional insured status and ask for the endorsement itself. Learn more about certificate holder vs. additional insured and how additional insured status shows on a COI.
Who Provides the COI?
The contractor does. They ask their insurance agent, broker, or carrier to issue a certificate naming you as the certificate holder, and the insurer sends it to them or straight to you. Only the insurer or its agent can issue a valid COI.
Each subcontractor should provide their own COI rather than relying on the general contractor’s. For example:
- A general contractor shares a COI before starting a renovation
- An electrician provides proof of workers’ compensation for their crew
- A landscaping company submits a COI for ongoing maintenance work
How to Request a COI From a Contractor
Don’t settle for a verbal yes when you ask whether a contractor is insured. Make a written request:
- State that you need proof of insurance, name the policy types you require, and say how long coverage must last. It should run at least through the end of the job.
- List your minimum limits and any endorsements, such as additional insured status or a waiver of subrogation.
- Give your company’s legal name and mailing address so you can be listed as the certificate holder.
- Set a deadline before the start date, and say where to send the certificate.
- When the COI arrives, check it against your requirements before work begins.
For wording you can reuse, see our guide on how to ask for a COI.
How Long Does It Take, and What Does It Cost?
Most COIs arrive within a few days, but some take a few weeks, so ask early. The certificate itself is free. The contractor pays for the insurance, not for proof of it.
When Should You Ask?
Always before work begins. Ask when you:
- Hire contractors or subcontractors for any project
- Bring on suppliers or delivery partners
- Lease or rent property to a third party
- Sign a new subcontract or renew an existing one
- Hire specialty trades for higher-risk work
Is It Rude to Ask a Contractor for Proof of Insurance?
No. Asking is due diligence, and on many projects it is a contract requirement. Professional contractors expect the request and usually respond quickly.
What Happens If a Subcontractor Has No Insurance?
Many hiring businesses make a current COI a condition of the contract: no coverage, no work. If a subcontractor works without coverage and something goes wrong, you may be held responsible for the injuries, property damage, legal fees, or claims that follow. An uninsured sub on your site also puts your own policy, and your own limits, in the line of fire.
How Do You Spot a Fake or Expired COI?
Treat every COI as a claim to verify, not proof to accept:
- Check the dates. Every policy should stay active for the full length of the project, not expire mid-job.
- Verify with the source. Contact the issuing broker or carrier to confirm the coverage, limits, and additional insured status.
- Watch for altered PDFs. Look for mismatched fonts, uneven formatting, or numbers typed over the original ACORD 25 layout.
- Check the issuer details. A missing authorized signature, a blank producer field, or a broker you can’t find are red flags.
For a full walkthrough, read insurance verification 101.
Limitations of a COI
- It is a point in time. A COI shows coverage on the day it was issued. Policies can be canceled, changed, or allowed to expire without automatic notice to you.
- It doesn’t change the policy. The policy language decides what is covered, excluded, or limited. A clean-looking COI cannot prevent a claim denial if the exclusions or endorsements don’t match your contract.
- It doesn’t insure you. You are only covered if you are added to the policy as an additional insured.
Key Construction COI Terms
Waiver of Subrogation
Subrogation lets an insurer that paid a claim recover the money from whoever caused the loss. A waiver of subrogation, often required in construction contracts, stops the contractor’s insurer from coming after you.
Exclusions
Exclusions limit or remove coverage in certain situations. Common construction exclusions include pollution, mold, subsidence, and faulty workmanship. Review every exclusion against the work being done.
Builder’s Risk
Builder’s risk insurance protects a building under construction, along with materials and equipment, from losses like fire, theft, and vandalism. Learn more about builder’s risk insurance.
How to Track COIs Across Every Subcontractor
One project can mean dozens of subcontractors, each with several policies and their own renewal dates. Staying compliant means tracking expirations, reviewing every endorsement, and chasing updated certificates, often across hundreds of pages. That is why many general contractors move from spreadsheets to certificate of insurance tracking software. For more on the rules you need to meet, see our guide to compliance in the construction industry.
How illumend, from myCOI, Helps Construction Teams
illumend gives you one place to collect, review, and track every subcontractor’s COI. You invite your third-party partners, they upload their certificates, and Lumie, illumend’s AI, reads each certificate against your requirements, flags what’s missing, and tells your partners in clear terms what to fix. With the Core plan, Lumie also reviews endorsements and other insurance documents. You see who’s covered and who isn’t without chasing emails.
See how it works for construction teams, or schedule a demo and we’ll show you how illumend fits your workflow.
Frequently Asked Questions
What does COI stand for in construction?
Certificate of insurance.
Is a COI the same as an insurance policy?
No. It is a one-page summary that proves coverage. It isn’t the policy and gives no coverage rights.
Who provides the COI, the contractor or the client?
The contractor gets it from their insurance broker or carrier and gives it to the client.
What is the most common construction COI form?
The ACORD 25, Certificate of Liability Insurance.
How do I verify a contractor’s COI is real?
Confirm the dates, limits, and endorsements directly with the issuing agent or carrier.
