By the Templateez Team · Licensed Attorney · June 2026

Subcontractor Documentation: What General Contractors Need From Every Sub

A general contractor on a $400,000 residential renovation hired a tile sub he had used twice before. Good work, fair price, showed up on time. No paperwork — just a handshake and a verbal scope. Six weeks into the project, the sub's employee fell off scaffolding in the bathroom and broke his wrist. The sub had let his workers' comp lapse two months earlier. The injured worker filed a claim against the GC. The GC's insurance carrier paid out $87,000 and then raised his premium by 40%. The tile work cost $9,200. The missing paperwork cost nine times that.

This is not unusual. We hear versions of this story from GCs constantly — the details change, but the pattern is always the same. A sub you trusted did not have the coverage you assumed they had, and you found out at the worst possible moment. The fix is not complicated. It is eight documents, collected before any sub touches the jobsite, no exceptions. Here is what they are and why each one matters.

1. Certificate of Insurance (COI) — With You as Additional Insured

This is the single most important document in your sub file. Not just proof that the sub has insurance — proof that you are covered under their policy as an additional insured. There is a massive difference.

A standard COI shows that the sub has general liability coverage. That protects the sub if they cause damage. But if a homeowner sues you for something the sub did — and they will, because the homeowner's contract is with you, not the sub — the sub's basic policy does not cover you. You need to be named as an additional insured on their policy. That means their insurer has a duty to defend you in claims arising from the sub's work.

What to verify on the COI:

• Policy dates — the policy must be active for the entire duration of the sub's work on your project, not just the day they hand you the certificate. If a six-month project starts in March and the sub's policy renews in July, you need an updated COI in July.
• Coverage limits — most GCs require subs to carry at least $1 million per occurrence and $2 million aggregate. Your own contract with the property owner may dictate minimums. Match them.
• Additional insured endorsement — look for your company name in the certificate holder box or on an attached endorsement form. If it is not there, the certificate is not enough.
• Umbrella or excess liability — on larger commercial projects, you may need subs to carry umbrella coverage above their primary limits.

Real scenario: A roofing sub provided a COI at the start of a project that ran eight months. The policy expired at month five. Nobody checked. At month seven, a shingle bundle fell off the roof and dented the homeowner's car and cracked their windshield. The sub's lapsed policy paid nothing. The GC's policy covered the $4,800 in damage plus the homeowner's rental car, and the GC could not recover from the sub's insurer because there was no active policy.

2. W-9 (Request for Taxpayer Identification Number)

If you pay a subcontractor more than $600 in a calendar year, you are required to issue a 1099-NEC. You cannot issue a 1099 without a W-9. This is not optional — the IRS penalty for failing to file a correct 1099 is $310 per form as of 2026, and it goes up if the IRS determines willful disregard.

Collect the W-9 before the first payment, not at year-end when the sub is unreachable and you are scrambling to file. The W-9 also confirms the sub's legal business name and tax classification — sole proprietor, LLC, S-corp — which matters for how you report the payments and whether backup withholding applies.

A secondary benefit: requiring a W-9 up front filters out subs who are not operating as legitimate businesses. If someone cannot or will not provide a tax ID, that tells you something important about how they run their operation.

3. License Verification

In most states, subcontractors performing electrical, plumbing, HVAC, roofing, and other specialty trade work are required to hold a valid state or municipal license. As the GC, you are responsible for verifying this. If an unlicensed sub performs work on your project and the building inspector catches it — or worse, something fails — you are liable.

What to capture:

• License number and issuing authority — state contractor licensing board, municipal office, or both depending on jurisdiction.
• License type and classification — a plumber with a journeyman license cannot pull permits in some states. An electrician with a residential license may not be qualified for commercial work.
• Expiration date — same logic as the COI. A license that expires mid-project is a license that does not cover the work done after expiration.
• Disciplinary history — most state licensing boards have online lookup tools. A sub with multiple complaints or a suspended license is a risk you want to know about before they are on your jobsite.

Copy the license. Do not just write down the number. If there is ever a dispute, you want the document itself in your project file.

4. Lien Waivers — Conditional and Unconditional

This is where GCs lose the most money — not from bad work, but from bad lien management. A mechanic's lien allows anyone who provided labor or materials on a project to place a lien on the property if they were not paid. That includes your subs, their material suppliers, and in some states, the sub's employees. Even if you paid the sub in full, if the sub did not pay their material supplier, that supplier can lien the property. The homeowner is now dealing with a cloud on their title, and they are blaming you.

The solution is a lien waiver process built into your payment schedule:

• Conditional lien waiver on progress payments — the sub signs this when they submit an invoice. It says: "I waive my lien rights for the amount of this payment, conditioned on actually receiving the payment." If the check bounces, the waiver is void and the sub retains their lien rights. This protects the sub while giving you documentation of the exchange.
• Unconditional lien waiver on final payment — the sub signs this when they receive their final payment. It says: "I have been paid in full and I unconditionally waive all lien rights on this project." No conditions, no contingencies. This is the document that clears the sub's lien rights permanently.

Real scenario: A GC on a $280,000 kitchen and bath remodel paid his concrete sub $34,000 for foundation work. No lien waivers were exchanged. The sub pocketed the money and did not pay his rebar supplier $11,600. The supplier filed a mechanic's lien on the homeowner's property. The homeowner was in the process of refinancing. The lien killed the refinance. The homeowner's attorney sent the GC a demand letter for the $11,600 plus $8,000 in legal fees plus the rate differential on the delayed refinance. The GC ended up paying $22,000 to resolve a problem that a $0 piece of paper would have prevented.

Many states have statutory lien waiver forms. Use them. A lien waiver that does not comply with your state's requirements may be unenforceable.

5. Subcontractor Agreement

A handshake is not a contract — or rather, it is, but it is the kind of contract where both sides remember different terms. A written subcontractor agreement defines the relationship in terms that hold up when things go wrong. And on construction projects, things go wrong.

Critical clauses in every sub agreement:

• Scope of work — exactly what the sub is doing and, just as importantly, what they are not doing. "Plumbing rough-in" means different things to different plumbers. Spell it out.
• Payment terms — how much, when, tied to what milestones, retainage percentage if applicable.
• Change order process — no extra work without a written, signed change order. This is the clause that prevents the "while you're at it" disputes.
• Insurance requirements — minimum coverage, additional insured requirement, obligation to maintain coverage throughout the project.
• Indemnification — the sub agrees to hold you harmless for claims arising from their work. This is your backstop when the COI is not enough.
• Cleanup and debris removal — sounds minor until a demolition sub leaves a dumpster full of debris for your framing crew to work around.

You can generate a basic independent contractor agreement through our document generator. For complex construction projects, you will want a construction-specific sub agreement reviewed by an attorney, but the generator gives you a solid starting framework for smaller jobs.

6. Safety Acknowledgment

OSHA does not care whether the person who fell off the scaffolding was your employee or your sub's employee. If it is your jobsite, you have a duty to ensure safe working conditions. A safety acknowledgment does three things:

• Confirms the sub received your site-specific safety requirements — PPE requirements, fall protection protocols, hot work permits, confined space procedures, whatever applies to your project.
• Establishes the sub's obligation to enforce safety with their own crew — you cannot supervise every sub's employees. The acknowledgment puts the sub on record that they are responsible for their workers' compliance.
• Creates a paper trail — if OSHA investigates an incident on your site, one of the first things they ask for is documentation that subs were informed of safety requirements. No documentation means no defense.

This does not need to be a 30-page safety manual. A one-page acknowledgment that covers the site-specific hazards, the required PPE, and the sub's agreement to comply is sufficient for most residential and light commercial projects. On larger commercial or industrial jobs, a full safety plan with daily toolbox talks is standard.

You can also generate a liability waiver through our document generator that covers the safety acknowledgment angle for simpler projects.

7. Workers' Compensation Certificate

This is separate from the general liability COI, and it is the one that causes the most expensive problems when it is missing. Workers' comp covers a sub's employees for injuries sustained on the job. Without it, the injured worker has limited options — and one of those options is filing a claim against you as the general contractor who controlled the jobsite.

In many states, if a sub does not carry workers' comp and their employee is injured on your project, your workers' comp policy is responsible. Your insurer pays the claim, and then your experience modification rate goes up, which raises your premiums for three years. On a policy that costs $35,000 a year, a single claim from an uninsured sub can add $10,000–$15,000 in annual premium increases.

Real scenario: A painting sub brought a crew of four to a residential exterior job. The sub was a sole proprietor who had exempted himself from workers' comp — legal in his state for the business owner, but his three employees were not exempt. He had no workers' comp policy. One of his painters fell from a ladder and broke his hip. The painter filed a claim against the GC's workers' comp. The GC's carrier paid $142,000 in medical and lost-wage benefits. The GC's mod rate went from 0.85 to 1.32, adding $16,400 per year to his premiums for the next three years. Total cost of not collecting a workers' comp certificate: $191,200.

What to verify:

• Policy is active and covers all employees — not just the sub as an individual.
• Classification codes match the work being performed — a sub insured for residential painting but performing commercial work may not be covered.
• Sole proprietor exemptions — some states allow sole proprietors to exempt themselves. That is fine for the owner, but any employees must be covered.

8. Scope of Work and Change Order Process

This is sometimes part of the subcontractor agreement and sometimes a separate document, especially when you have a master agreement with a sub you use regularly and the scope changes project to project. Either way, it needs to exist in writing for every project.

The scope of work should specify:

• Exactly what work is included — not "electrical," but "rough-in wiring for 42 outlets, 18 switches, and 12 recessed light fixtures per the attached electrical plan, sheet E-1."
• Materials — who furnishes them? If the sub, what brand and grade? If you, when will they be on site?
• Exclusions — what is not included? Permit fees, inspection coordination, dumpster access, temporary power — these default assumptions cause disputes when they are not spelled out.
• Timeline — start date, duration, and what milestones they need to hit for the next trade to start.

The change order process is equally important. It should state that no work beyond the agreed scope will be performed without a written change order signed by both parties, and that the change order must include the additional cost, the revised timeline, and the impact on other trades. Without this, you end up with subs performing extra work, billing you for it, and you having no leverage to dispute it because nobody said "stop" in writing.

When to Collect These Documents

Before the sub sets foot on your jobsite. Not after the first week. Not "when they get around to it." Before day one.

This is where most GCs fail. They know they should collect these documents, and they intend to, but the project is moving fast and the sub is already there and the documents can wait. They cannot. Every day a sub works on your project without current insurance, a signed agreement, and a lien waiver process is a day you are exposed to risks that can cost ten or fifty times the value of the sub's work.

Build a sub onboarding packet. Make it a fillable form — our general contractor intake forms include a subcontractor documentation section with checkboxes for each of these eight items. When a sub is onboarded, every box gets checked before they get a start date. No exceptions for subs you have used before. No exceptions for small jobs. No exceptions for "he's my brother-in-law." The $9,200 tile sub from the opening of this article was someone the GC had used before and trusted. Trust does not pay workers' comp claims.

The Real Cost of Skipping Paperwork

We have talked to dozens of GCs who learned this lesson the expensive way. The pattern is always the same: the sub paperwork felt like overhead, until it was the only thing that could have prevented a five- or six-figure loss. A lien waiver costs nothing. A COI verification takes five minutes. A W-9 is a one-page form. The total time to collect all eight documents from a new sub is about 30 minutes. The cost of not collecting them can be a business-ending event.

If you are building out your documentation system from scratch, start with our guide to the forms every trade business needs. For intake-specific guidance, see our general contractor intake form guide and our piece on what to capture on the first call. All of our trade-specific forms — plumbing, electrical, HVAC, roofing, painting, concrete and masonry, demolition, and 45 more — include subcontractor coordination sections built for the specific trade.