Subcontractor Certificate of Insurance Requirements: What GCs Should Require and Verify

A subcontractor certificate of insurance is the document a sub gives the general contractor to prove it carries the coverage its subcontract requires, usually commercial general liability with completed operations, workers compensation, commercial auto and an umbrella, with the GC and the project owner named as additional insured. General contractors require it so an injury or property claim caused by a sub lands on the sub's policy, not the GC's. The certificate has to be verified, current, and on file before the crew mobilizes.

If you run jobs as a general contractor or construction manager, the subcontractor COI is one of the few things standing between a sub's mistake and your own insurance program. Get the requirements right, flow them down from the prime contract, and verify each certificate before the trade starts, and the risk sits where the contract puts it. Miss a limit, an endorsement, or a renewal, and you are the one absorbing the claim. This guide covers what to require, how flow-down works, and how to verify each certificate without drowning in PDFs.

What insurance should a general contractor require from subcontractors?

Most general contractors require commercial general liability of at least $1 million per occurrence and $2 million aggregate with completed operations, workers compensation per state law, commercial auto liability, and an umbrella or excess policy from each subcontractor. Higher-risk trades are held to higher limits. Every sub should name the GC and the owner as additional insured on a primary and noncontributory basis, with a waiver of subrogation.

The exact limits come from your subcontract, which in turn should mirror the prime contract you signed with the owner. Coverage is not one-size-fits-all across trades. A painter and a steel erector carry very different risk, and most GCs scale the requirements to match.

Treat the table as a starting point, not legal or insurance advice. Your subcontracts, the prime contract and state law set the actual requirements. For a deeper look at how coverage and limits get set across any vendor relationship, see our guide on vendor insurance requirements.

What does it mean to flow down insurance requirements?

Flow down means the general contractor passes the insurance terms from the prime contract with the owner into each subcontract, so the limits, additional insured wording, waiver of subrogation and completed operations the owner requires are mirrored down to every sub. This keeps the whole contract chain compliant and ensures the certificate you check against a sub matches exactly what the owner is relying on you to deliver.

When flow-down breaks, the GC is exposed. If the owner requires the prime to carry $5 million in umbrella limits and name the owner as additional insured, but a subcontract only requires $1 million and forgets the owner, a serious claim from that sub can blow straight through to the GC's own program. Reading the prime contract insurance exhibit and copying its requirements into each subcontract is the single most important step in setting up COI compliance on a job.

Why does the GC need to be additional insured on a subcontractor policy?

Being named as additional insured gives the general contractor access to the subcontractor's policy and defense costs when a claim arises out of that sub's work. Without it, the GC is left relying on its own coverage after a sub causes an injury or property damage, which raises the GC's loss history and premiums. Subcontracts almost always require additional insured status for both the GC and the owner.

Additional insured status is created by endorsement, not by checking a box on the certificate. The common forms are CG 20 10 for ongoing operations and CG 20 37 for completed operations. A certificate that simply lists you as certificate holder, or marks an additional insured box with no endorsement attached, does not give you the coverage you bargained for. If you want the full distinction, our explainer on additional insured vs certificate holder walks through it.

Should subcontractors carry completed operations coverage?

Yes. Completed operations coverage responds to claims that surface after a subcontractor finishes its work, such as a defect that fails months after the crew left the site. Construction defect claims often appear long after a job closes out, so general contractors require completed operations on the certificate and additional insured status that extends to it through a CG 20 37 endorsement, not just general liability for ongoing work.

This is one of the most overlooked checks on a subcontractor COI. A certificate can show a strong general liability limit and still be missing completed operations entirely, which leaves the GC exposed for exactly the kind of late-emerging claim that costs the most. Our deeper guide on completed operations coverage explains how it works and how to confirm it.

How does a general contractor verify subcontractor insurance?

A general contractor verifies subcontractor insurance by collecting a certificate from each sub, checking the coverages and limits against that subcontract, confirming the GC and owner are named as additional insured with the right endorsements, and monitoring expiration so coverage stays current through the job. The goal is to verify each certificate before the crew mobilizes, because chasing a missing COI after a trade is already working is far harder.

A practical verification checklist for each sub:

• Confirm the named insured on the certificate matches the company on the subcontract.
• Check each coverage limit against the subcontract requirement, including the umbrella.
• Confirm completed operations is included, not just ongoing operations.
• Verify the GC and owner are listed as additional insured, ideally with the endorsement attached.
• Check for waiver of subrogation and primary and noncontributory wording where required.
• Confirm the policy effective and expiration dates cover the work period, and set a renewal reminder.
• Spot-check the carrier's rating and that the agent is legitimate.

For step-by-step verification, including how to spot a fake or altered certificate, see how to verify a certificate of insurance.

Can a subcontractor work before its certificate of insurance is verified?

A subcontractor should not mobilize before a compliant certificate is on file and verified. Once a crew is working, any insurance gap is already open and harder to fix, and the GC is exposed for whatever happens in the meantime. Most general contractors gate both mobilization and payment on a current, compliant COI, so a sub that has not cleared compliance does not start and does not get paid.

The hard part is holding that gate under schedule pressure across several jobs at once. When a project manager is staring at a start date, it is tempting to let a crew begin and sort the paperwork later. Software that flags a missing or short certificate before the crew arrives is how GCs keep the mobilization gate from slipping. COI tracking for general contractors reads each subcontractor certificate, checks it against the subcontract, and shows a clear pass or flag for every trade on every active job.

How do general contractors track subcontractor COIs across many jobs?

General contractors track subcontractor COIs by collecting a certificate from each sub, checking it against that subcontract, and monitoring expiration across every job in one place. A spreadsheet per project works until several jobs run at once, each with its own trade list and renewal calendar, at which point renewals slip and completed operations goes unchecked. Most growing GCs move to software that reads each certificate and flags anything short or expired.

The certificate of insurance is one piece of a larger subcontractor onboarding flow. Once a sub clears insurance, the next steps usually involve getting the subcontract signed and collecting the rest of the paperwork. Many GCs handle the subcontract and change-order signatures with an online document e-signing tool, pull data from W-9s, licenses and other onboarding documents using AI document data extraction, and issue and track purchase orders to subs and material suppliers through dedicated purchase order management software. Keeping the COI verified and current is what makes the rest of that onboarding worth doing.

The bottom line for general contractors

Subcontractor certificate of insurance requirements come down to three habits: require the right coverage by trade and flow it down from the prime contract, verify each certificate against that subcontract before the crew mobilizes, and monitor renewals so no sub works on expired coverage. Do those consistently across every job and the risk a sub creates stays on the sub's policy. To put it on autopilot, COI tracking for general contractors reads every subcontractor certificate and tells you who is cleared to work and who is not.