Connecticut Subcontractor Insurance Requirements: What General Contractors Need to Know

TL;DR: Connecticut requires general liability and workers' compensation from virtually every subcontractor — sole proprietors can opt out of WC but corporate officers must file Form 6B with the CT Workers' Compensation Commission to get an exemption. If a sub has no WC certificate and no valid exemption, the GC becomes the employer of record for WC purposes.

Connecticut is a mid-sized state with an outsized compliance burden. The combination of mandatory WC for nearly all workers, a strict independent-contractor test, non-resident withholding rules, and a prevailing wage law that kicks in at relatively low project thresholds makes it one of the more demanding states for GC document management. This guide walks you through every requirement — insurance, licensing, lien waivers, and 1099s — so you know exactly what to collect before a sub picks up a hammer.

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Contractor Licensing in Connecticut

Connecticut licenses contractors through the Department of Consumer Protection (DCP). Before you bring a sub on-site, confirm they hold the right credential for their trade:

• Home Improvement Contractor (HIC) Registration – Required for any residential remodeling, repair, or renovation project valued over $200. GCs and subs doing residential work both need this registration. The DCP maintains a public search tool where you can verify status in seconds.
• New Home Construction Contractor (NHCC) Registration – Separate from HIC; required for new residential construction.
• Electrical, Plumbing, and HVAC – Each trade requires its own state license (journeyman and master levels). Unlicensed electrical or plumbing work is a Class D felony in Connecticut.
• Commercial GCs – Connecticut does not have a statewide commercial GC license, but municipalities may require a local permit puller's license. Confirm with the local building department for every project.

What to collect: A copy of the sub's current DCP registration or trade license certificate. Cross-check the license number against the DCP database — some contractors carry expired cards and hope no one checks.

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General Liability Insurance Requirements in Connecticut

Connecticut does not set a statutory minimum GL limit for private projects. In practice, the market and your contract drive the numbers. Typical requirements:

Project Type	Minimum GL Per Occurrence	Aggregate
Residential remodel	$500,000	$1,000,000
Commercial (small)	$1,000,000	$2,000,000
Commercial (mid-large)	$1,000,000 – $2,000,000	$2,000,000 – $4,000,000
Public / municipal	$1,000,000+	$2,000,000+

Your subcontract should define the exact limits you require. Whatever you require, verify it on the certificate of insurance (COI) before the sub starts work — not the day of a claim.

Additional insured: Connecticut courts generally enforce additional-insured endorsements as written. Require the CG 20 10 (ongoing operations) and CG 20 37 (completed operations) endorsements — not just a blanket certificate note. The certificate alone doesn't create additional-insured status; only the endorsement does.

Certificate of insurance tips:

• Require 30-day cancellation notice (some policies default to 10 days)
• Confirm the policy period covers the entire duration of the sub's work
• If the sub uses a claims-made GL policy, make sure the retroactive date predates when they first started work for you

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Workers' Compensation in Connecticut

This is where Connecticut GCs face the most exposure. Get these rules right.

Who needs WC coverage?

Connecticut Workers' Compensation Act (CGS § 31-275 et seq.) requires WC coverage for every employee, including part-time workers, with almost no exceptions. The key word: employees. The question for subcontractors is always whether they qualify as independent contractors.

The Connecticut Independent Contractor Test

Connecticut uses a strict ABC test (CGS § 31-222(a)(1)(B)(ii)) to determine if a worker is an independent contractor for WC purposes. All three prongs must be satisfied:

• A – The worker is free from control and direction of the hiring party in performing the work
• B – The worker performs work outside the usual course of business of the hiring party
• C – The worker is customarily engaged in an independently established trade, occupation, or business

Failing any one prong means the worker is an employee, and the GC may be liable for WC coverage. The Connecticut Workers' Compensation Commission and DOL take this seriously — misclassification audits are common.

Bottom line: A sub who shows up with a pickup truck and no certificate of insurance does not automatically qualify as an independent contractor. If they fail the ABC test, you're on the hook for their WC premiums and any injuries.

WC Exemptions in Connecticut

Sole proprietors: Not required to carry WC for themselves (only for their employees). Get a written statement confirming they have no employees and are working as a sole proprietor.

Partnerships: Partners can elect to exclude themselves from WC coverage. If a partner is excluded, confirm it in writing.

Corporate officers: Up to two corporate officers may withdraw from WC coverage by filing Form 6B (Voluntary Withdrawal from Workers' Compensation Coverage) with the CT Workers' Compensation Commission. The exemption is not automatic — the Form 6B must be on file. Request a copy of the filed form or verify with the WCC.

LLC members: Connecticut law treats LLC members similarly to corporate officers for WC exemption purposes, but the specifics depend on the LLC structure. When in doubt, require the WC certificate and let the sub's attorney sort out their exemption eligibility.

What to collect

For every subcontractor:

1. Certificate of insurance showing WC coverage, or
2. Proof of valid exemption (Form 6B for corporate officers; written sole-proprietor attestation)

If you accept a certificate, confirm the policy is active — call the carrier or use their online verification portal. Certificates can be backdated or forged; a quick phone call catches problems that cost $10,000+ later.

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Connecticut Prevailing Wage Requirements

Connecticut has its own prevailing wage law (CGS § 31-53) separate from the federal Davis-Bacon Act. It applies to public works contracts — state, municipal, and quasi-public projects — above these thresholds (verify current thresholds with the CT DOL, as they have changed in recent years):

• New construction: $1,000,000 or more
• Renovation/repair: $100,000 or more

When prevailing wage applies:

• Every sub and lower-tier sub must pay the applicable CT DOL wage rate for each trade classification
• Certified payroll reports are required weekly — Connecticut uses its own reporting system (eCPR) in addition to federal WH-347 requirements for federally funded projects
• GCs are responsible for collecting and submitting their subs' certified payroll reports

If your project hits either threshold, build certified payroll collection into your subcontract from day one. Chasing down weekly reports from reluctant subs after work has started is a nightmare, and the GC can have payments withheld for non-compliance.

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W-9 Collection and 1099 Requirements

The federal rules apply in Connecticut: collect a W-9 from every sub you pay $600 or more in a calendar year, and file a 1099-NEC by January 31 of the following year. The IRS penalty for failure to file is $310 per form.

Connecticut-specific: Non-Resident Contractor Withholding

Connecticut has a rule that catches many GCs off guard. If you pay a non-resident individual (someone who does not live in Connecticut) for services performed in Connecticut, you may be required to withhold 6.99% of the payment and remit it to the CT Department of Revenue Services using Form CT-941.

Exemptions from withholding:

• The non-resident sub certifies (on CT Form 590) that they have a CT tax account and will file a CT return
• The payment is to a corporation (C or S corp) — generally, withholding applies to non-resident individuals and pass-throughs whose owners are non-residents
• The payment is for materials, not services

Practical tip: When onboarding out-of-state subs, include Form CT-590 in your packet alongside the W-9. A completed CT-590 releasing you from withholding is much easier to get before work starts than after you've already paid the sub.

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Lien Waivers in Connecticut

Connecticut's mechanic's lien law is governed by CGS § 49-33 et seq. Key points:

No pre-lien notice required

Unlike Georgia, Texas, and many other states, Connecticut does not require a preliminary notice (sometimes called a "notice to owner" or "Notice of Right to Lien") from subcontractors before they can file a lien. This means a sub or supplier can file a lien even if you had no idea they were unpaid.

What this means for GCs: Collect lien waivers from every sub and major supplier at each payment milestone. Don't wait for final payment.

Lien filing deadline

A subcontractor has 90 days from the date of last work (or last material delivered) to file a lien. This is shorter than many states' 120-day windows, but 90 days goes by fast when you're managing a busy project.

Lien foreclosure deadline

A filed lien must be foreclosed (enforced in court) within one year of filing, or it expires.

Lien waiver forms

Connecticut does not have statutory lien waiver forms (unlike states like California or Texas). You can use your own forms or industry-standard forms. The key elements:

• Conditional waiver on progress payment – Claimant waives lien rights for the specific payment described, effective only when payment clears
• Unconditional waiver on progress payment – Claimant waives lien rights through the payment date unconditionally
• Conditional waiver on final payment – Waives all lien rights effective when final payment clears
• Unconditional waiver on final payment – Waives all lien rights unconditionally

Always use conditional waivers until the check has cleared. An unconditional waiver given before payment clears leaves you exposed if the check bounces.

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Connecticut Compliance Checklist

Before a subcontractor starts work on any Connecticut project, confirm you have:

• Valid CT contractor license or registration (trade license, HIC, NHCC as applicable)
• Certificate of general liability insurance (correct limits, additional insured endorsements CG 20 10 / CG 20 37, 30-day cancellation notice)
• Workers' compensation certificate or valid exemption (Form 6B for officers; sole-proprietor attestation as applicable)
• Completed W-9 (federal)
• Completed CT Form 590 (for non-resident individual subs)
• Signed subcontract including lien waiver provisions
• Confirmed prevailing wage status if project is a public works contract

Set calendar reminders to check GL and WC certificate expiration dates 30 days before they lapse. A lapsed certificate on a WC policy is not just a paperwork problem — if a worker gets hurt while coverage has expired, the GC is exposed for the full claim.

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The Cost of Getting This Wrong

Connecticut's compliance failures compound quickly:

• Uninsured sub injury: The GC becomes the employer of record for WC purposes. A single lost-time injury can cost $50,000–$500,000 or more, plus experience modification rate (EMR) impact that follows you for three years.
• Non-resident withholding failure: The CT DRS can assess the GC for unpaid withholding plus interest and penalties. The GC can't recover from the sub after the fact if the sub is long gone.
• Lien from unknown supplier: No pre-lien notice required means surprise liens. Without signed waivers, you may pay twice for the same work.
• Prevailing wage violation: The CT DOL can withhold public contract payments and debar contractors from future public work. Penalties include back wages plus liquidated damages.

PaperBoss tracks certificate expiration dates, exemption status, and W-9/CT-590 collection for every subcontractor so nothing falls through the cracks. When a certificate lapses, you get an alert before the sub sets foot on your site — not after.

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Frequently Asked Questions

Does Connecticut require a license for commercial general contractors?

Connecticut does not have a statewide commercial GC license. However, residential GCs and subs need a Home Improvement Contractor (HIC) registration from the DCP for work over $200 in value. Electrical, plumbing, and HVAC trades require separate state trade licenses regardless of project type. Always verify local permit requirements with the municipal building department.

Can a sole proprietor sub skip workers' compensation in Connecticut?

Yes — a sole proprietor with no employees is not required to carry workers' compensation for themselves. However, you need written confirmation that they genuinely have no employees. If they hire day laborers even occasionally, those workers must be covered, and the GC can become liable if they're not.

What is Connecticut Form 6B?

Form 6B (Voluntary Withdrawal from Workers' Compensation Coverage) is filed by a corporation's officers with the Connecticut Workers' Compensation Commission to exempt those officers from WC coverage. Up to two officers can file. The form must be on file with the WCC — a verbal claim of exemption is not sufficient. Ask for a copy of the filed form.

Is Connecticut a prevailing wage state?

Yes. Connecticut's prevailing wage law (CGS § 31-53) applies to public works projects — generally new construction contracts over $1,000,000 and renovation/repair contracts over $100,000. GCs must collect certified payroll reports from every tier of subcontractor on covered projects. Thresholds can change; verify with the CT DOL before assuming your project is under the threshold.

Do I need to withhold state income tax from payments to out-of-state subs?

Potentially. Connecticut requires 6.99% withholding on payments to non-resident individuals for services performed in Connecticut, unless the sub provides a completed Form CT-590 certifying they have a CT tax account and will file a CT return. Payments to corporations are generally exempt. Get Form CT-590 at the start of every engagement with an out-of-state individual sub.

How long does a subcontractor have to file a mechanics lien in Connecticut?

Ninety days from the date of last work or last materials delivered. Connecticut does not require a pre-lien notice, so you may not know a lien is coming. Collect signed lien waivers (conditional on payment) at every payment milestone to protect yourself.

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Start the Job Right

Connecticut's compliance rules aren't complicated once you know them — but they move fast and the penalties for missing a step are expensive. Verify licenses before signing subcontracts, collect certificates before work starts, and get lien waivers every time you cut a check.

If you're managing more than a handful of subs, tracking all of this manually in spreadsheets becomes a part-time job in itself. PaperBoss automates certificate collection, expiration tracking, and document reminders so you can focus on running the project instead of chasing paperwork. Start a free trial and get your Connecticut subcontractor compliance under control.