How to Verify Subcontractor Insurance: A 3-Layer Approach

TL;DR: Real subcontractor insurance verification has three layers: the COI surface check (90 seconds for entity name, dates, limits, certificate holder), endorsement verification (request CG 20 10, CG 20 37, CG 20 01, CG 24 04, WC 00 03 13), and direct producer confirmation by phone. Skipping layers two and three is how GCs end up with COIs that look perfect but provide zero coverage when a claim hits.

Collecting a Certificate of Insurance from a subcontractor is the easy part. Verifying that the certificate reflects real, adequate, and enforceable coverage is where most GCs either do it right or skip straight to exposure. This post walks through a three-layer verification process that catches the majority of coverage gaps without requiring a risk manager on staff.

Layer 1: The Certificate

The first layer is the surface verification that everyone does. Get the COI, look at it, confirm:

• Named insured matches the sub's legal business name exactly, not a DBA, not a prior entity, not an affiliate.
• Effective and expiration dates cover the project period without gaps.
• Coverage limits meet your contract requirements on every line (CGL, Auto, Umbrella, Workers' Comp).
• Certificate holder is your company, spelled correctly.
• Description of Operations box references Additional Insured, Primary and Non-Contributory, and Waiver of Subrogation language.
• Producer name and contact info are real and verifiable.

Layer 1 takes about 90 seconds per certificate and catches the most obvious problems: wrong entity, expired coverage, inadequate limits, missing endorsement references. If a certificate fails Layer 1, send it back immediately.

But Layer 1 is only the surface. The COI is a summary. The real coverage lives in the policy itself.

Layer 2: The Endorsements

Layer 2 verifies that the endorsement forms referenced on the COI actually exist on the policy. This means requesting the actual endorsement pages from the sub or their producer, not trusting the COI's summary.

What to request

• CG 20 10 (Ongoing Operations Additional Insured endorsement)
• CG 20 37 (Completed Operations Additional Insured endorsement)
• CG 20 01 (Primary and Non-Contributory endorsement) or confirmation that the AI endorsement has PNC language built in
• CG 24 04 (Waiver of Subrogation for CGL)
• WC 00 03 13 (Waiver of Subrogation for Workers' Comp)

Any producer familiar with construction should send these within a day. A sub who can't or won't produce endorsement pages is a red flag.

What to check on each endorsement

• Your company is listed or a blanket provision applies via written contract
• The endorsement edition date is current (not an old version with narrower coverage)
• No exclusionary language limits the coverage
• The endorsement is actually attached to the policy shown on the COI (not a different policy)

For more detail on what goes wrong at this layer, see our post on the 8 endorsement clauses that break COI compliance.

Layer 3: The Policy and Exclusions

Layer 3 is the deep review. For large contracts, high-risk work, or projects in plaintiff-friendly jurisdictions, you review the policy itself, including:

• Declarations page (shows actual coverage in force)
• Exclusions (where the policy refuses to cover certain risks)
• Conditions (procedural requirements for coverage to apply)
• Attached endorsements (the cumulative effect of all the add-ons and modifications)

Layer 3 catches things like residential exclusions, contractual liability limitations, sole employee exclusions, "your work" exclusions, and earth movement exclusions that would defeat coverage in a real claim. Most GCs don't do Layer 3 themselves. They rely on their insurance broker, their attorney, or a dedicated policy review service for high-risk projects.

When to Use Each Layer

Not every sub needs all three layers. Scale the verification to the risk:

• Low-risk subs (finish trades, small contracts, repeat vendors with good history): Layer 1 only. Standard COI verification.
• Moderate-risk subs (most commercial work): Layers 1 + 2. Verify the actual endorsement pages.
• High-risk subs (structural, electrical, high-elevation, large contracts, high-risk jurisdictions): All three layers, including policy review by your broker or attorney for the highest-stakes contracts.

Automating What You Can

The manual work of requesting, storing, and tracking all of this documentation is where most GCs fall behind. PaperBoss automates the collection and storage piece: every sub uploads their COI and supporting endorsement documents via a secure link, PaperBoss organizes everything by sub and project, tracks expirations, and alerts you before anything lapses.

What PaperBoss doesn't do is the Layer 2 and Layer 3 judgment calls. Those still require a human reading the documents and comparing them to contract requirements, but the workflow automation means you spend your time reviewing rather than chasing and filing.

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Verification in Practice

For a GC processing a moderate-sized commercial project with 20 subcontractors, a realistic verification workflow looks like:

1. Day 1 of onboarding: Send COI request via PaperBoss upload link. Sub uploads within 48 hours or gets automated reminders.
2. Day 2: Layer 1 review. Check limits, dates, named insured, endorsement references. 90 seconds per sub.
3. Day 3: Request endorsement pages from subs whose work category triggers Layer 2 (moderate and high-risk subs). Most producers turn these around within 24-48 hours.
4. Day 4-5: Layer 2 review of endorsement pages. Flag concerns, escalate to sub's producer or your broker.
5. Day 5-10: For high-risk or large contracts, route policy documents to your broker or attorney for Layer 3 review.
6. Project start: Subs with complete verified documentation are cleared to work. Subs with open items are held until resolved.
7. Throughout project: Monitor expirations, refresh certificates on renewal, re-verify Layer 2 endorsements on policy renewals.
8. At closeout: Final verification, collect final lien waivers, archive documentation for statute of repose retention.

This workflow takes discipline and time but is dramatically less expensive than the alternative, which is discovering a gap during a claim.

Frequently Asked Questions

Do I need to verify every sub at all three layers?

No. Scale the verification to the risk. Most subs warrant Layers 1 and 2. High-risk or large-contract subs warrant all three.

How long does Layer 1 verification take?

About 90 seconds per certificate once you know what you're looking at. Our post on how to read a COI walks through the ACORD 25 field by field.

What if a sub refuses to provide endorsement pages?

Treat it as a red flag. A producer familiar with construction should routinely provide endorsement pages. Refusal usually means either the endorsements don't exist, the producer is unfamiliar with construction insurance, or the sub is hoping to slip through without scrutiny.

Can I rely on my insurance broker to verify for me?

Your broker can handle Layer 3 policy review on a consulting basis, especially for large contracts. For routine COI verification across many subs, brokers typically can't do it at scale. Internal verification with software support is the practical approach.

Does PaperBoss do the endorsement review automatically?

No. PaperBoss collects, stores, and tracks the documents but doesn't perform the legal or insurance judgment calls required for endorsement and policy review. Human review is still required for Layer 2 and 3.

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This article is for educational purposes only and does not constitute legal or insurance advice. Consult a licensed construction insurance broker or attorney for specific policy review questions.