Tracking subcontractor certificates of insurance: what a COI is and why the dates matter

You collected the certificate before the sub started. It was current, the limits looked right, you filed it, and you moved on to the next fire. Eight months later that sub's electrician puts a screwdriver through a water line — and when you go to the file, the certificate expired in the spring. Now the loss that should have flowed to their insurer is looking for the next policy in line, which is very often yours. A certificate of insurance is only worth the day it's still in force, and the whole discipline of COI tracking is making sure you find out about a lapse before the claim does.

This is a plain-English look at what a certificate of insurance actually is (and isn't), the coverages and endorsements a general contractor should require from subs, why the expiration date is the single most important field, and how to track the whole roster so nobody works your site uncovered.

What a certificate of insurance is — and what it isn't

A certificate of insurance (COI) is a one-page summary, issued by an insurance agent or broker, that states a party carries certain policies, with certain limits, effective for a certain period. On a construction project, the general contractor requires one from every subcontractor as evidence they carry their own coverage — so that when a sub causes a loss, the sub's insurance responds, not the GC's.

Here's the part that trips people up: a COI is informational only. It is not the insurance policy, it doesn't amend or guarantee coverage, and it can be accurate the day it's issued and meaningless a month later if the policy is cancelled. The certificate is a snapshot, not a contract. That's exactly why tracking matters — the document you filed proves coverage as of its issue date, and nothing after. Only the policy itself, and the issuing agent, can confirm coverage is actually in force today.

The coverages to require

What you require is set by your contract and your own risk tolerance, but a typical subcontractor COI on a commercial job shows four coverages:

• Commercial General Liability (CGL). The core policy — covers third-party bodily injury and property damage arising from the sub's work. This is the one that answers when their crew damages the building or hurts someone. Watch the each-occurrence and aggregate limits.
• Automobile Liability. Covers the sub's vehicles — relevant the moment a truck is backing into your site or hauling material.
• Workers' Compensation. Covers the sub's own employees if they're injured. Without it, an injured worker of an uninsured sub can reach up the chain toward the GC. In most states it's not optional.
• Umbrella / Excess Liability. Sits on top of the others to raise the effective limits — often required on larger jobs to hit a contractual threshold the base policies don't reach.

Each of these has its own expiration date, and they rarely line up. A sub can be perfectly current on GL and lapsed on Workers' Comp — which is why tracking each policy's date separately, not one date per sub, is the difference between a real compliance picture and a false sense of security.

The endorsements that do the real work

Coverage limits get the attention, but on construction contracts the endorsements are often what actually protect the GC. Three come up again and again:

• Additional Insured. This extends the sub's policy to cover you (the GC, and often the owner) for liability arising out of the sub's work. Without it, the sub's insurer defends the sub — not you — even when you're pulled into the claim for the sub's mistake. This is the endorsement contracts fight over for good reason.
• Waiver of Subrogation. Stops the sub's insurer from turning around after paying a claim and coming after you to recover. It keeps a loss from ping-ponging back up the chain.
• Primary & Non-Contributory. Says the sub's coverage pays first and in full before yours is touched — rather than the two policies sharing the loss and dragging your carrier (and your experience rating) in.

A certificate can show generous limits and still leave you exposed if these endorsements aren't in place. That's why a good register logs them as their own Yes/No fields per sub — a current policy without the required Additional Insured endorsement is a compliance gap, not a pass.

Why the expiration date is the field that matters most

Everything above is a one-time check at onboarding. The expiration date is the field that has to be watched continuously — because coverage doesn't fail loudly. A policy lapses quietly on its renewal date, the sub keeps showing up to work exactly as before, and nothing looks different until the day something goes wrong and the certificate turns out to have expired weeks ago. The gap between "we have their COI" and "their COI is current today" is where GCs get hurt.

Watching it by hand across twenty or forty subs, each with four policies on different renewal cycles, is exactly the kind of task humans forget until it's too late — the same problem professionals face tracking their own license and CE renewals. The fix is the same, too: let the dates watch themselves. A register that computes days-to-expiry from today and flags what's expired, expiring soon (say within 30 days), or missing a required policy turns an impossible mental checklist into a glance — and gives you the window to chase a renewed certificate before the old one lapses, not after.

Running COI compliance without a risk manager

Big GCs have a risk department and third-party COI-verification services. A small builder can still run tight compliance from one file with a few habits:

• No certificate, no site. The simplest and strongest rule: a sub doesn't start until a current, complete COI with the required endorsements is on file. Enforced once, it saves a dozen scrambles later.
• Log each policy's date separately. One row per sub, but a date per coverage. The lapse you miss will be the one policy you weren't watching.
• Check the endorsements, not just the limits. Additional Insured and the others are Yes/No compliance items — a big limit without them is still a gap.
• Chase renewals on the 30-day warning, not the expiry. Certificates take time to reissue. The amber flag is your cue to email the sub's agent now, while there's still runway.
• When it matters, confirm with the agent. Before a high-risk phase or after any doubt, verify the policy is actually in force — the certificate is a starting point, not proof.

A subcontractor's insurance is one of the main things standing between their mistake and your balance sheet — but only while it's actually in force. Collect the certificates, require the endorsements, and above all watch the dates, because the whole protection evaporates the moment a policy lapses and nobody notices. Make the dates watch themselves, and a lapsed COI becomes a flag you catch on a Tuesday instead of a claim you discover too late.

This is general information about organizing certificate-of-insurance records, not insurance, risk-management, or legal advice. A certificate of insurance is informational only and does not confer or verify coverage; required coverages, limits, and endorsements are set by your contract, and only the issuing insurer or agent can confirm a policy is in force. Consult a qualified insurance and legal professional for your project's requirements.