Answer-first summary: A certificate of insurance (COI) with expired dates, missing additional insured endorsements, wrong policy type, or inadequate limits can expose your business to uncovered losses — even when a vendor hands you a valid-looking document. Review every field before a subcontractor sets foot on site. Who this is for: general contractors, property managers, staffing firms, event producers, and any business that collects COIs from vendors or subs.
TL;DR — Key Takeaways
- An ACORD 25 certificate is informational only and does not create or modify coverage — the underlying policy controls.
- The most dangerous red flags are expired policy dates, missing additional insured endorsements, and claims-made policies without a stated retroactive date.
- "30-day cancellation notice" language on a COI is not contractually enforceable unless it appears in an endorsement to the policy itself.
- Limits on the certificate should match or exceed your contract's minimum requirements — shortfalls become your problem after a loss.
- Always request the actual endorsement pages (AI endorsement, waiver of subrogation) alongside the certificate.
Why COIs Exist — and What They Cannot Do
A Certificate of Insurance is a standardized one-page snapshot, typically on ACORD Form 25 (liability) or ACORD Form 28 (property), that summarizes an insured's coverage at a point in time. Certificates are issued by the insured's agent or broker and sent to third parties who require proof of insurance — general contractors, building owners, event venues, and similar.
What a COI does: - Confirms coverage type, carrier, policy number, and effective/expiration dates as of the issuance date - Names certificate holders and additional insureds (if the underlying endorsement exists) - Lists limits of liability for each coverage line
What a COI cannot do: - Alter, extend, or create coverage that does not exist in the underlying policy - Guarantee coverage will remain in force (policies can be cancelled) - Substitute for an actual endorsement
This distinction — certificate vs. endorsement — is the foundation of every COI dispute.
The 8 Biggest Certificate of Insurance Red Flags
1. Expired or Mismatched Policy Dates
The "Policy Effective" and "Policy Expiration" dates on the certificate must cover the full project or contract period. If a subcontractor's general liability expires on September 30 and your project runs through December 15, any bodily injury or property damage claim arising after September 30 will fall to you.
Check: Match the certificate dates against every phase of your project schedule, including punch-list and warranty periods.
2. Additional Insured Listed on the Certificate but No Endorsement Attached
Writing a party's name in the "Additional Insured" box of ACORD 25 is meaningless unless the carrier has issued an endorsement — typically CG 20 10 (ongoing operations) and CG 20 37 (completed operations) — amending the policy. Many carriers automatically include AI status via a blanket endorsement triggered by written contract, but you cannot assume this.
Check: Request the actual AI endorsement pages. If the sub uses a blanket AI endorsement, ask for the endorsement number and confirm it's triggered by your contract.
3. Claims-Made Policy with No Retroactive Date Shown
General liability can be written on an occurrence basis (the incident date triggers coverage) or a claims-made basis (the date the claim is reported triggers coverage). Claims-made policies carry a retroactive date — work performed before that date is excluded. A certificate that shows "Claims-Made" with a retroactive date that post-dates the start of the subcontractor's work on your project means prior incidents are uninsured.
Check: If you see "Claims-Made," verify the retroactive date precedes your first contract date with that sub.
4. Inadequate Limits
Your contract may require $1,000,000 per occurrence / $2,000,000 aggregate for general liability. If the certificate shows $500,000 per occurrence, the gap is not covered — it becomes a gap in your risk transfer program.
| Coverage Line | Common Contract Minimum | Watch-for Shortfall |
|---|---|---|
| GL Per Occurrence | $1,000,000 | Less than $1M for trade contractors |
| GL General Aggregate | $2,000,000 | Per-project aggregate vs. blanket aggregate |
| Auto Liability | $1,000,000 CSL | Split-limit policies that don't equal $1M combined |
| Workers Comp | Statutory | "Waived" WC with no evidence of sole-prop exemption |
| Umbrella / Excess | $5,000,000+ (large GC) | Umbrella that doesn't follow form to underlying GL |
| Professional Liability | $1,000,000 per claim | Design-build subs, engineers, IT vendors |
5. Missing or Defective Waiver of Subrogation
A waiver of subrogation prevents the insured's carrier from suing you (the certificate holder or additional insured) after paying a claim to the insured. Without it, a subcontractor's workers comp carrier can subrogate against you for a job-site injury even though you're named as additional insured on the GL.
Check: Confirm a Waiver of Subrogation endorsement (WC 00 03 13 for workers comp) is listed on the certificate and that the underlying endorsement was actually issued.
6. "Project" General Aggregate vs. Blanket Aggregate
A blanket general aggregate resets to $2,000,000 across all of a sub's projects. If the sub has a bad loss elsewhere that year, your project could be left with a depleted aggregate. Request a per-project aggregate endorsement (CG 25 03 or CG 25 04) for high-value or long-duration projects.
7. Wrong Entity Named as Insured
Verify the "Named Insured" on the certificate exactly matches the legal entity in your contract. "ABC Plumbing LLC" and "ABC Plumbing Inc." are different legal entities. If the entity that signed your contract isn't the named insured on the policy, you may have no enforceable coverage.
8. Unauthorized or Altered Certificates
ACORD Form 25 certificates must be issued by a licensed agent or broker. Altered certificates — where someone changes dates, limits, or policy numbers after issuance — do occur and constitute insurance fraud. If a certificate looks tampered with, or if the issuing agent's information is missing, call the carrier directly to verify.
How to Review a COI in 7 Steps
- Confirm the form version — ACORD 25 (2016/03) or later for liability; ACORD 28 for property.
- Check the producer's information — a licensed agency name, address, and phone number should be listed. Call them to verify issuance if anything looks off.
- Match the named insured to your contract — entity name must be identical.
- Verify all policy dates cover your full contract period, including warranty or maintenance tails.
- Confirm each coverage type and limit against your contract's minimum insurance requirements schedule.
- Request and review actual endorsement pages for Additional Insured status and Waiver of Subrogation on every applicable line.
- Check for per-project aggregate and retroactive date (for claims-made policies).
Real-World Example: Electrical Subcontractor on a $3.2 Million Office Fit-Out
A general contractor in Texas hires an electrical sub for a $3.2M commercial tenant improvement. The sub provides a COI showing:
- GL limits: $1M / $2M ✓
- Umbrella: $5M ✓
- Workers Comp: Statutory ✓
- Additional Insured: GC listed in the "Description of Operations" box
Eighteen months into the project, an employee of the electrical sub suffers a severe electrical burn. The workers comp carrier pays $480,000 in medical and indemnity benefits — then subrogates against the GC for $320,000, alleging the GC's site-safety protocol contributed to the injury.
The GC assumed the "Additional Insured" notation on ACORD 25 extended to workers comp. It does not. Workers comp additional insured is a separate concept, and subrogation waivers for WC require a specific endorsement (WC 00 03 13). The sub's certificate never included that endorsement. The GC's own GL carrier ultimately settled the subrogation claim, and the loss went onto the GC's general liability loss runs — raising future premiums at renewal.
This scenario is illustrative. Actual outcomes depend on policy language, state law, and contractual indemnity terms.
FAQ: Certificate of Insurance Red Flags
Q: Can I rely on the 30-day cancellation notice printed on ACORD 25? A: No. The standard ACORD 25 certificate states it will endeavor to provide notice but that failure to do so imposes no obligation on the insurer. Enforceable cancellation notice requires an endorsement to the policy — not just language on the certificate. Ask for a "Notice of Cancellation" endorsement if your contract requires it.
Q: What's the difference between a certificate holder and an additional insured? A: A certificate holder receives the certificate and may get cancellation notices. An additional insured is a party added to the policy by endorsement, giving them direct rights to defense and indemnity under the policy for covered claims. These are not the same thing, and most standard ACORD 25 certificates do not automatically make a certificate holder an additional insured.
Q: Should I accept a COI that shows a carrier I've never heard of? A: Verify the carrier's AM Best financial strength rating (aim for A- VIII or better for most commercial risks) and confirm the carrier is licensed in your state through your state's Department of Insurance lookup. An admitted carrier that becomes insolvent may leave claims unpaid, though state guaranty funds provide limited protection.
Q: How do I know if the certificate was altered or fraudulent? A: Call the issuing agent directly using a phone number you look up independently — not one printed on the potentially altered certificate. You can also call the carrier's policyholder verification line. ACORD certificates include anti-fraud notices, but altering them does still occur.
Q: My contract says subs need $2M per occurrence. The sub's certificate shows $1M per occurrence but a $5M umbrella. Does that count? A: It depends on how your contract is written. If the contract requires "$2M per occurrence" in the primary general liability policy, an umbrella does not satisfy that requirement, even if total coverage exceeds $2M. Umbrella policies typically have a self-insured retention or drop-down provisions that may not apply exactly like primary coverage. Consult your attorney about contract language.
Q: What is a "per-project" aggregate and when do I need it? A: A blanket GL general aggregate applies across all of an insured's projects during the policy year. If the sub has a large loss on another job, your project could face a depleted aggregate. A per-project aggregate endorsement (ISO CG 25 03 or CG 25 04) resets the aggregate separately for your project. Require it for projects exceeding $500,000 or with multi-year schedules.
Q: Do sole proprietors need to carry workers comp? A: Rules vary by state. Many states allow sole proprietors to exempt themselves from workers comp requirements, but the exemption must be documented — typically with a state-issued exemption certificate. A COI that shows no workers comp for an individual laborer working on your job site is a red flag; verify their exemption status. [verify state — requirements differ significantly]
Q: Can a vendor's agent send me a backdated certificate? A: Intentionally backdating a certificate to show coverage that did not exist is insurance fraud. If you suspect a certificate has been backdated, contact the carrier directly and, if warranted, your state's Department of Insurance fraud hotline.
Why Morrow for COI Review and Vendor Insurance Compliance
1. Independent agency — multiple carrier relationships. Morrow places commercial accounts across a broad panel of admitted and surplus lines carriers. When your subcontractor's limits or coverage type don't meet your contract's requirements, we can often find a solution without forcing you to replace a vendor mid-project.
2. COI review built into our client workflow. We help our commercial clients build insurance requirements schedules and review incoming COIs for common red flags — not just rubber-stamping whatever a sub sends. We flag missing endorsements, inadequate limits, and coverage gaps before they become claims problems.
3. Endorsement-level verification. We don't stop at the face of ACORD 25. When clients need it, we coordinate with the sub's broker to obtain actual endorsement pages confirming Additional Insured status, Waiver of Subrogation, and per-project aggregate.
4. Claims advocacy when it matters. If a loss triggers a coverage dispute — a carrier denies an additional insured tender, or a waiver of subrogation is challenged — our team advocates for our clients through the claim resolution process. We document the paper trail from the beginning.
5. Specialization in contractor and commercial real estate risk. General contractors, specialty trades, property managers, and commercial landlords are a core part of our book. We understand the contract insurance requirements in these industries and how they translate into actual policy language. [Morrow to confirm specific trade verticals and licensed states]
Get a Quote or Request a COI Review
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Trust strip: Morrow (Afthonea Inc., DBA Morrow) is an independent commercial insurance agency. [Morrow to confirm: licensed states, NPN, carrier appointments, Google/BBB review count and rating.]
Related Resources
- Commercial General Liability Insurance: The Complete Guide
- Additional Insured Endorsements Explained
- Workers Compensation Insurance for Contractors
- How to Build a Vendor Insurance Requirements Program
- Certificate of Insurance: What It Is and What It Covers
Author: Sarah Kimball, CPCU, CIC — Commercial Lines Practice Lead, Morrow (Afthonea Inc.). Sarah has 14 years of experience placing commercial P&C programs for contractors, real estate operators, and professional services firms.
Published: June 2026 | Last updated: June 2026
Sources: - ACORD Corporation — ACORD Form 25 (Certificate of Liability Insurance), Form 28 (Evidence of Property Insurance) - Insurance Services Office (ISO) — CG 20 10, CG 20 37 (Additional Insured endorsements), CG 25 03, CG 25 04 (Per-Project Aggregate endorsements), WC 00 03 13 (Waiver of Subrogation — Workers Comp) - National Association of Insurance Commissioners (NAIC) — Model Certificate of Insurance Disclosure Act - AM Best — Financial Strength Rating methodology - State Departments of Insurance (carrier licensing verification) — [verify your state's DOI portal] - Insurance Information Institute (Triple-I) — Understanding Commercial General Liability - Associated General Contractors of America (AGC) — Standard Insurance Requirements for Subcontractors