Construction Certificate of Insurance: What to Check on Every COI

A Certificate of Insurance (COI) is a one-page summary document that confirms a contractor or subcontractor carries insurance. On every commercial construction project, GCs collect COIs from every subcontractor before work begins — and owners collect them from the GC. The problem is that a COI is only a summary, not the actual policy, and it can be outdated, incomplete, or misleading. Knowing how to read a COI, what coverages to require, and what red flags to look for is what separates a professional preconstruction process from one that creates liability exposure the moment a worker is injured on site.

What a COI Is — and What It Isn't

A Certificate of Insurance is issued by an insurance agent or broker to evidence that a policy exists. The standard form used in construction is ACORD 25 (ACORD 28 for property insurance). Key limitations:

• A COI is not a policy. It summarizes coverage but does not supersede the actual policy language. If the certificate says "additional insured" but the endorsement doesn't exist on the actual policy, the additional insured status may not hold.
• A COI is a point-in-time snapshot. Coverage shown was valid when the certificate was issued. Policies can be cancelled or not renewed after the certificate date. Always require 30-day cancellation notice language.
• The certificate holder is not automatically an additional insured. Being listed as "certificate holder" means you receive the document — it does not grant you rights under the policy. Additional insured status requires a specific endorsement.

Required Coverages in Commercial Construction

Subcontract agreements and owner contracts specify minimum insurance requirements. Standard commercial construction coverages:

Commercial General
Liability (CGL)

Covers bodily injury and property damage arising from operations. Typical minimums: $1M per occurrence / $2M aggregate. On larger commercial projects: $2M/$4M or higher. CGL covers third-party claims — an injured visitor, a neighbor's property damaged during excavation. It does not cover the contractor's own work (that's completed operations / builder's risk). Check both the per-occurrence and aggregate limits separately.

Workers'
Compensation (WC)

Covers medical costs and lost wages for employees injured on the job. Statutory limits by state — required in all states for employers with employees. Most critical coverage to verify. If a sub's employee is injured and the sub doesn't carry WC, the GC's WC policy (and premium) is typically assessed. Always confirm WC is in force. Sole proprietors are often excluded — verify they carry or waive in writing per state law.

Employer's Liability

Covers claims by employees against the employer for negligence (above WC statutory limits). Shown on the same line as WC. Minimum: $500K/$500K/$500K (bodily injury by accident / bodily injury by disease policy limit / bodily injury by disease per employee).

Commercial Auto

Covers owned, hired, and non-owned vehicles used in operations. Critical for subs who drive vehicles to the job site. Minimum: $1M combined single limit. Confirm "hired and non-owned auto" is included — this covers employees using personal vehicles for work. Missing auto coverage is a common gap on small sub COIs.

Umbrella / Excess
Liability

Sits above CGL, auto, and employer's liability, providing additional limits when underlying coverage is exhausted. Typical minimum on commercial projects: $5M–$10M. Umbrella triggers only after underlying limits are exhausted. Verify the umbrella "follows form" with underlying policies and that it covers the same lines (CGL + auto + EL). A cheap umbrella that only covers CGL leaves auto and EL gaps.

Professional Liability
(E&O)

Covers errors and omissions in professional services — required for design-build contractors, MEP engineers, and any sub providing design services. Also called Design Professional Liability. Separate policy from CGL. If your project includes any design responsibility by the contractor, require E&O. Standard minimum: $1M per claim / $2M aggregate.

Additional Insured: The Most Important Endorsement

Being named as an Additional Insured (AI) on a subcontractor's CGL policy gives you rights under their insurance — you can make a claim against their policy if you're sued for something their work caused. This is the core risk transfer mechanism in construction: each sub covers the tier above them for claims arising from their work.

Critical: A COI that says "Additional Insured" in the description box is not sufficient. The AI endorsement must exist on the actual policy. The gold standard is ISO endorsement CG 20 10 (ongoing operations) + CG 20 37 (completed operations). Require the actual endorsement forms, not just certificate language. Some insurers issue CG 20 33 instead — acceptable but slightly narrower. Blanket AI endorsements (automatically adding AI per contract) are common and acceptable; named AI endorsements are also fine.

Certificate Holder

The entity listed to receive the COI document and cancellation notices. Being a certificate holder does not give you insurance rights. Any party can be a certificate holder. Your company name and address here means you'll receive notice of cancellation — nothing more.

Additional Insured

An entity with actual rights under the sub's policy — you can tender claims to their insurer. Must be added by endorsement to the actual policy, not just noted on the certificate. Requires an AI endorsement (CG 20 10/37 or blanket AI per contract). This is what you need — not just certificate holder status.

Primary & Non-Contributory

When a claim involves multiple parties (sub, GC, owner), each party's insurer may try to share the loss with other policies. Primary and non-contributory language in the sub's policy means their insurance pays first, without contribution from your policy. Without this language, your insurer and theirs may dispute who pays and in what proportion — slowing claim resolution and potentially exhausting your own limits on the sub's claim.

Require "Primary and Non-Contributory" language from all subs in the subcontract and verify it appears in the COI's description box or by separate endorsement. ISO endorsement CG 20 01 provides this. It must be specifically requested — it's not automatic on most policies.

Waiver of Subrogation

Subrogation is the right of an insurer who paid a claim to sue the party responsible for the loss. If your insurer pays a claim and then sues your subcontractor (recovering from the sub), the sub relationship is damaged and the sub's rates increase. A Waiver of Subrogation prevents your insurer from suing your sub after paying a claim — keeping the contractual relationship intact and preventing the claim from circling back to you.

Require waiver of subrogation on all policies — GL, WC, and auto. The WC waiver is especially important because WC insurers routinely subrogate against third parties. ISO endorsement WC 00 03 13 is the standard WC waiver of subrogation form.

8 Red Flags When Reviewing a COI

Expired policy dates. Check every expiration date against the project schedule. A policy that expires mid-project is not compliant. Require renewal COIs before expiration — and hold payment if coverage lapses.

Limits below contract minimums. If the subcontract requires $2M CGL and the COI shows $1M, the sub is non-compliant. Do not allow work to begin. Requiring evidence of higher limits can be done mid-policy via endorsement — sub's broker can issue a new cert showing correct limits.

No workers' compensation. A sub showing "WC Excluded" or leaving WC blank may be using independent contractors or operating in a state that allows WC exclusions for small employers. Verify the sub has no W-2 employees before accepting exclusion — or require the sub to carry WC regardless.

Missing hired and non-owned auto. A sub whose employees drive personal trucks to the job site needs HNOA coverage. If the COI only shows "owned autos" and the sub has no company-owned vehicles, they have a gap.

Additional insured by certificate notation only. "Additional insured per contract" written in the description box is insufficient without a corresponding endorsement on file. Call the sub's broker and request the actual endorsement form number and confirmation the endorsement is attached to the policy.

Aggregate limits already partially eroded. The COI shows aggregate limits but not how much has been used. If a sub has had claims during the policy year, their remaining aggregate may be less than shown. On high-risk trades, request a loss run or confirm aggregate is fully intact.

Umbrella doesn't follow form. An umbrella policy that only covers CGL (not auto, not employer's liability) leaves gaps. Verify the umbrella form shows it follows underlying lines and that underlying limits match — a common trick is to lower underlying limits (cheaper) and rely on umbrella, but some umbrellas have "retained limits" that don't trigger until a minimum self-insured threshold.

Named insured doesn't match the contracting entity. The policy is in the name of "John Smith DBA Smith Electric" but the subcontract is with "Smith Electrical Services LLC." Legal entities matter for insurance coverage. Verify the named insured on the policy matches the legal entity signing the subcontract — or get written confirmation from the broker that the legal entity is covered.

COI Tracking Best Practices

On a project with 20–40 subcontractors, COI tracking becomes an administrative workflow. Core practices:

• Collect COIs before the subcontract is executed — not on the first day of work.
• Set calendar reminders 30 days before each policy expiration and require renewal certificates before the old policy expires.
• Hold the Notice to Proceed until COI requirements are met. This is the only enforcement lever with real teeth.
• Retain copies of all COIs and endorsements in the project file — insurance claims can arise years after project closeout, and you need to be able to prove coverage existed.
• Require COIs from sub-subcontractors on projects where lower-tier subs are authorized. Flow-down insurance requirements in your subcontracts.

Missing scope is a different kind of liability

COIs protect you from insurance gaps. Complete plan sets protect you from scope gaps — the kind that show up as change orders after the contract is signed. SheetIntel reviews construction documents before bid, identifying coordination conflicts, missing specifications, and ambiguous scope that drive disputes. Start with a free plan review.

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