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Sub-Subcontractor COIs: How to Handle Insurance for Lower-Tier Subs

By SubCover HQ · Updated Nov 2, 2026 · 3 min read

Your electrician brings in a low-voltage crew. Your roofer hires a tear-off crew for two days. Those lower-tier subcontractors (sub-subs) are working on your job, but you never signed a contract with them, and you may not even know their names. If one of them is uninsured and someone gets hurt, the claim tends to roll uphill to the sub that hired them, then to you.

Why lower-tier subs are a risk

• Workers' comp gaps. If a sub-sub has no workers' comp, its injured worker may look to the next employer up the chain. Many insurers also charge the hiring contractor premium at audit for payments to uninsured subs.
• Liability gaps. An uninsured sub-sub that causes property damage or injury leaves your sub's policy, and possibly yours, to absorb it.
• Exclusions on your sub's policy. Some general liability policies limit or exclude coverage for work done by subcontractors unless the sub collected certificates and agreed requirements from them. Your sub's agent can tell you whether its policy has a condition like this.

Put flow-down requirements in your subcontract

The fix starts on paper. Your subcontract can require the sub to:

1. Get your approval (or at least give notice) before hiring any lower-tier sub.
2. Require each lower-tier sub to carry insurance at least as broad as the sub's own requirements, or a stated minimum.
3. Have lower-tier subs name you, the owner, and anyone else you require as additional insureds, with waiver of subrogation where required.
4. Collect and keep each lower-tier sub's certificate and endorsements, and send copies to you on request or before that sub starts work.

Your attorney should write the actual clause. Our free insurance requirements generator can give you a starting list of coverages and limits to hand them.

What to collect

For each lower-tier sub on site, you want the same basics you collect from your direct subs: a current ACORD 25 issued by their agent, general liability and workers' comp at minimum, additional insured endorsements if your contract requires them, and policy dates that cover the work. Either collect these yourself or require your sub to collect them and send you copies.

Practical ways to keep track

• Ask at the pre-job meeting. "Will anyone other than your own employees be on site?" Write down the answer.
• Check the sign-in sheet. Unfamiliar company names on site logs or badges are a cue to ask for certificates.
• Tie payment to paperwork. Some GCs hold progress payments until certificates for every lower-tier sub on the job are on file.
• Track them like direct subs. Lower-tier certificates expire too. Record each policy date and chase renewals the same way.

Key takeaways

You can't check certificates you don't know exist. Require notice and flow-down insurance in your subcontract, ask who will actually be on site, and collect lower-tier certificates before those crews start. SubCover HQ can collect and track lower-tier certificates alongside your direct subs, for $99/month.

Frequently asked questions

Do sub-subcontractors need to provide a certificate of insurance?

If they work on your job, it's wise to require it. Most GCs require their subs to collect certificates from any lower-tier subs and send copies on request.

Who is responsible for collecting a sub-sub's COI?

Usually the subcontractor that hired them, under flow-down terms in your subcontract. Many GCs also collect copies directly.

Does my sub's policy cover its uninsured subcontractors?

Not necessarily. Some policies limit coverage for work by subcontractors unless certain requirements were met. Ask the sub's agent.

This guide is general information, not insurance or legal advice. Policy wording and contract requirements vary; your insurance professional and attorney determine what you should require.