What Insurance Do Subcontractors Need? A GC's Complete Checklist

Hiring an uninsured subcontractor is one of the most common and most expensive mistakes a general contractor makes. When a sub without coverage causes property damage or injures someone on your job site, the claim does not disappear. It comes back to your policy, your deductible, and your renewal premium. This article is a practical checklist for GCs who want to hire subs without inheriting their liability: what insurance to require, how to verify it, how to read a certificate of insurance, and how to build a verification process that does not slow down your jobs.

Why Uninsured Subs Are a Direct Risk to Your Business

The legal relationship between a general contractor and a subcontractor creates shared exposure. When a sub causes an accident on your job site, injured parties often name both the sub and the GC in any resulting lawsuit. The logic is straightforward: you hired the sub, supervised the job site, and had the primary contractual relationship with the property owner. Even if the sub was entirely at fault, you may be named in the claim.

If the sub carries adequate GL insurance with you named as an additional insured, their policy responds to the claim. Your policy is protected.

If the sub has no insurance, or their policy has lapsed, the claim has nowhere to go except to your own GL policy. You absorb the deductible. Your claims history takes the hit. Your renewal premium increases. And if the claim exceeds your policy limits, you face personal or business exposure beyond what your insurer will pay.

Subcontractor insurance requirements in your contracts are not bureaucratic formality. They are risk transfer.

The Standard Insurance Requirements for Subcontractors

The baseline insurance package you should require from every subcontractor you hire includes:

General liability insurance. At minimum, $1 million per occurrence and $2 million aggregate. For commercial projects or high-risk trades (roofing, electrical, structural steel), require $2 million per occurrence and $4 million aggregate. The limits should match or exceed what you carry on your own policy.

Workers compensation. Required in most states for any sub with employees. Workers comp protects you from claims by the sub's workers on your job site. If a sub's employee is injured and the sub does not have workers comp, that injured worker can potentially pursue a claim against you as the site-controlling party. Require workers comp certificates from every sub who has employees, and verify the certificate is current before they start work.

Commercial auto. If the sub will be driving vehicles on or to your job site, require a commercial auto policy. Many small sub operations miss this and are using personal vehicles for business use, creating the same coverage gap that affects GC operations.

Professional liability (when applicable). For subs whose work involves design, engineering consultation, or any advisory function, require errors and omissions coverage. This applies to MEP engineers, architects working as subs, and design-build specialty contractors.

Umbrella or excess liability. On larger commercial projects, require an umbrella policy that extends the sub's GL limits. $1 million in umbrella coverage on top of a $1M/$2M GL policy is a common requirement for mid-size commercial work.

How to Read a Certificate of Insurance (What to Check)

The standard COI form is the ACORD 25. Every insurance certificate you receive from a sub should be on this form. Here is what to verify in each section:

Insured name. The name at the top of the certificate must match the legal name of the subcontractor's business entity as it appears in your contract. A certificate for "Smith Plumbing LLC" does not automatically cover "John Smith" as a sole proprietor.

Insurer name and AM Best rating. Confirm the insurer is a licensed company in your state and, for larger projects, check their AM Best financial strength rating. A rated "A-" or better insurer is the standard commercial requirement. Avoid accepting certificates from unrated carriers on significant jobs.

Policy type. Verify you are looking at occurrence-based GL policies, not claims-made. Occurrence policies cover incidents that happen during the policy period regardless of when the claim is filed. Claims-made policies only cover claims filed while the policy is active. For construction work where claims can surface years later, occurrence coverage is essential.

Policy dates. The policy must be active on the dates the sub will be working on your site. A certificate with an expiration date in two months needs to be renewed before that date or you stop work until a new certificate arrives.

Liability limits. Confirm the per occurrence and aggregate limits match what you required in your subcontract.

Additional insured. Look for your company name in the "Additional Insured" section or in the certificate remarks. If you are not listed as an additional insured, the certificate shows the sub has insurance, but you are not protected by it. This is one of the most common mistakes in sub certificate verification.

Workers comp certificate holder. Workers comp certificates should ideally reference the specific job or list your address as the work location. A generic certificate that does not reference your project may not respond to a claim on your specific site if a dispute arises.

Additional Insured Endorsements: What They Mean and When to Require Them

Being listed as a certificate holder on a COI means you receive a copy of the certificate. It does not give you any coverage protection.

Being listed as an additional insured means you are named on the sub's policy and the insurer has an obligation to defend and indemnify you in covered claims arising from the sub's work. This is the designation that actually matters.

When to require additional insured status:

• On every project where the sub's work is physically connected to work you are responsible for
• On any project where your contract with the property owner requires it
• On all jobs where a claim arising from sub work could involve you in the resulting lawsuit (which is most jobs)

The additional insured endorsement should be on the sub's policy, not just noted on the certificate. Request a copy of the endorsement itself for projects where the stakes are significant. A certificate can say "additional insured" in the remarks section, but the actual endorsement is what the insurer is bound by.

Primary and non-contributory endorsement. Require this on commercial projects. It specifies that the sub's policy is primary (pays first) and non-contributory (your own policy is not required to contribute) when both policies might otherwise respond to the same claim. Without this language, your insurer may argue that both policies should share the loss.

Waiver of subrogation. Some project owners require this from GCs. Pass the requirement down to your subs. A waiver of subrogation prevents the sub's insurer from suing you to recover money paid on a claim arising from your instructions or site conditions.

Building an Insurance Verification Process That Doesn't Slow Down Jobs

The mistake most GCs make is checking sub insurance once at the start of a project and never again. Policies cancel, lapse on renewal, or are modified mid-project. A sub who was insured on day one may not be insured in month four.

Pre-hire checklist. Before any sub signs a contract, require:

• Current ACORD 25 GL certificate with you listed as additional insured
• Workers comp certificate (if they have employees) or exemption documentation
• Commercial auto certificate (if they will bring vehicles on site)
• Completed W-9 for tax purposes

Do not allow a sub to start work without all required certificates in hand. This rule needs to be enforced consistently or it means nothing.

Renewal tracking. Log every sub's certificate expiration date in a spreadsheet or project management system. Set a reminder 30 days before expiration. If the sub does not provide a renewed certificate before the old one expires, work stops.

Mid-project verification for long jobs. On any project that runs longer than six months, request updated certificates at the midpoint. Policies renew annually, and a sub who carries coverage at the start of a long project may not renew mid-project.

Certificate verification service. For larger GC operations managing many subs simultaneously, certificate management software (ACORD-based platforms, or tools built into project management systems like Procore) automates tracking and sends renewal reminders automatically. The time investment pays for itself on the first lapsed coverage issue it catches.

Frequently Asked Questions

What happens if a sub's insurance lapses mid-project? Work should stop until the sub provides proof of current coverage. The risk of allowing a sub to continue uninsured is that any incident during that period has no insurance to back it up. Most subcontracts include a provision that lapses are a default condition allowing the GC to terminate the sub agreement.

Is it enough to just collect COIs without checking them? No. A certificate that names the wrong entity, shows inadequate limits, uses a claims-made form, or expires before the project ends is a problem. Someone in your organization needs to actually review each certificate against your requirements, not just file it.

Can I require subs to cover their own subcontractors? Yes. Your subcontract should require your subs to flow down the same insurance requirements to their sub-tiers. You are responsible for the work performed on your site regardless of the number of layers of subcontracting. Sub-tier insurance requirements protect you from claims originating two or three levels down the chain.

What if a small sub cannot afford the required limits? You have two options: fund the difference yourself by adding them to your own policy as an insured (with significant risk and cost implications), or find a different sub. Accepting inadequate coverage to fill a labor gap is a risk decision with real financial consequences.

Does requiring additional insured status cost the sub more? Usually not significantly. Adding an additional insured endorsement to an existing GL policy typically costs $25 to $100 per project endorsement, or may be included as a blanket endorsement at no extra charge on some policies. It is not a meaningful cost barrier, and any sub who resists this requirement is a red flag.

Your sub verification process is only as strong as your follow-through. Require the insurance, check the documents, track the expirations, and stop work when coverage lapses. That process protects your business, your clients, and the workers on your job sites.