Subcontractor Onboarding Checklist (10 Required Documents)
Subcontractor onboarding is the process of collecting, verifying, and filing the documents every general contractor needs before a new sub sets foot on a job site. This checklist covers all 10 documents — not just the COI — so you start every relationship with full compliance coverage from day one.
Why document collection matters before work starts: A single unlicensed or uninsured sub can expose your GC license and create liability that outlasts the project. Most compliance failures aren't from bad contractors — they're from GCs who assumed credentials were in order and never confirmed it. Collecting these documents before the first day of work closes that gap.
Certificate of Insurance (COI)
Request an ACORD 25 certificate listing General Liability, Workers' Compensation, and Employers' Liability coverage. The COI must come from the sub's insurer or agent — not a PDF the sub emailed you last year.
- General Liability ($1M per occurrence / $2M aggregate)
- Workers' Compensation (statutory limits)
- Commercial Auto (if sub operates vehicles)
- Your org named as Additional Insured (not just Certificate Holder)
- Policy expiration date is current
- Coverage limits meet your contract minimums
Use TrackMyVendor's COI tracking to get automatic expiration alerts 30 days before any sub's COI lapses.
W-9 (Request for Taxpayer Identification Number)
Collect IRS Form W-9 before the first payment — not at 1099 time. If you pay a sub more than $600 in a calendar year without a valid W-9 on file, you are required to withhold 24% backup withholding. The entity name on the W-9 must match the name on the contract and license.
State Contractor License (verified live)
Do not accept a photocopy of the license as verification. Licenses can be suspended or revoked after the paper was printed. Look up the license directly in the state database and confirm active status and correct classification for the work being performed.
- Texas: TDLR lookup (tdlr.texas.gov) + TECL for electricians
- California: CSLB license check at cslb.ca.gov
- Florida: DBPR license search at myfloridalicense.com
- Oregon: CCB lookup at oregon.gov/ccb — Oregon uses "registration" for general contractors
- Washington: L&I contractor lookup at lni.wa.gov
Signed Subcontractor Agreement
A fully executed agreement — both parties signed — covering scope of work, payment terms, indemnification, lien waiver requirements, insurance minimums, and dispute resolution. An unsigned agreement is unenforceable.
Business Entity Documentation
Certificate of Good Standing (or equivalent) confirming the sub is operating as a valid legal entity in the state. For sole proprietors operating under a DBA, a copy of the DBA filing. This document also confirms the legal name matches the W-9, COI, and contract.
Workers' Compensation Exemption Certificate (if applicable)
If a sub claims an exemption from Workers' Comp requirements, collect the state-issued exemption certificate — not a verbal claim. Rules vary sharply: Texas is the only state that does not require most private employers to carry Workers' Comp. Florida allows construction sole proprietors to file for exemption but limits the number of officers per entity.
Conditional Lien Waiver
Collect a signed conditional lien waiver before payment; exchange it for an unconditional waiver after payment clears. In Texas, lien waivers for residential projects must use the statutory form under Texas Property Code Chapter 53 to be enforceable — custom forms may not be valid.
Direct Deposit / ACH Authorization Form
If paying via ACH, collect a signed authorization form with bank name, routing number, and account number. ACH fraud targeting GC payroll is increasing — use a separate signed form, not just a voided check. This document also serves as evidence of the business relationship for IRS audit purposes.
Background Check Consent (conditional by project)
On federal, municipal, school district, or healthcare facility projects, collect a signed consent form from the sub's principals and, depending on your contract, their workers. Background check requirements flow down from the owner's prime contract — review it before determining whether this document is required.
Project Safety Acknowledgment
A signed acknowledgment that the sub has read and agrees to your project Safety Plan and Site Safety Rules. On OSHA-regulated sites, record that the sub's foreman has completed required safety training (OSHA 10 or OSHA 30). OSHA multi-employer worksite doctrine holds GCs responsible for hazards on a job site even if created by a sub — this document is your evidence of due diligence.
Quick-reference: the full checklist
How to verify each document — not just collect it
Collecting a document and verifying it are two different things. Here's what verification actually means for the four highest-risk documents:
COI
Request directly from the sub's insurer or agent — not the sub. The Additional Insured endorsement and the Certificate Holder fields are different fields on the ACORD form; confirm both are correct. If a COI lists you only as Certificate Holder, you are not protected in a claim.
State license
Go directly to the state database. The contractor license lookup for Texas, Florida, and California covers the states where most subcontractor license issues arise. Check status, classification, and expiration — all three.
W-9
Validate the TIN format matches the entity type before submitting to payroll. The IRS provides free TIN matching for payers at tin.gov — this catches incorrect TINs before 1099 season rather than after the IRS penalty notice arrives.
Subcontractor agreement
Confirm both parties have signed — an email saying "looks good" is not a signature. Keep a countersigned copy in your vendor file. The agreement should reference the specific project to avoid ambiguity about which project the indemnification obligation covers.
How often to re-collect these documents
Onboarding documents are not one-and-done. Here are the re-collection cadences most GCs miss:
Annually at minimum; immediately when the sub's coverage changes or a policy renews. Set an alert 30 days before expiration.
Texas TDLR renews annually or biennially by license type. California CSLB and Florida DBPR are biennial. Oregon CCB is annual. Set a monitoring alert rather than relying on the sub to notify you.
Re-collect when the sub's business name, entity type, address, or TIN changes. Also re-collect if you paid more than $600 in a year and don't have a signed copy on file before January 31.
Re-execute for each new project scope. Standing agreements should be reviewed annually for currency — insurance requirements and indemnification language in older agreements may not reflect your current risk posture.
Re-collect every 1–2 years or when the sub reports a change in entity structure. Certificates of Good Standing have no expiration date but go stale — a 3-year-old certificate is not evidence of current good standing.
Managing subcontractor documents at scale
If you have five subs, a shared folder works. If you have 25 or more, manual tracking breaks down in predictable ways: COIs expire mid-project without anyone noticing, licenses lapse between renewal and your next check, W-9s go missing before 1099 season. The paperwork you collected at onboarding doesn't stay valid — it has an expiration clock running on it from day one.
TrackMyVendor monitors license status, COI expiration, and W-9 status automatically — and sends alerts before anything lapses, so you're not finding out about a compliance gap after an incident.
Frequently asked questions
What documents should I collect from a subcontractor before they start work?
Before a subcontractor begins work, collect at minimum: (1) Certificate of Insurance with General Liability and Workers' Compensation coverage, (2) completed W-9, (3) current state contractor license number verified against the live state database, (4) signed subcontractor agreement, and (5) proof of business entity status. For projects with federal, municipal, school, or healthcare requirements, add background check consent and a project safety acknowledgment. Collecting these documents after work begins creates legal and financial exposure if an incident occurs during the gap.
Do I need a new W-9 from a subcontractor every year?
Not automatically. A W-9 remains valid until the sub's business name, entity type, address, or Tax Identification Number changes. Request a new W-9 when any of those change. For 1099-NEC filing, you need a valid W-9 on file — if you paid a sub more than $600 in the prior year and don't have one, request it immediately. IRS backup withholding of 24% applies on payments made without a valid W-9 on file.
Can I accept a copy of a subcontractor's license instead of looking it up?
No. A copy of a license certificate shows what the license looked like on the day it was issued, not today. Contractor licenses can be suspended, revoked, or lapsed between the time a sub provides their certificate and the time they show up on your job site. Always verify license status live in the state database: Texas TDLR, California CSLB, Florida DBPR, Oregon CCB, or Washington L&I. On large projects, consider automated license monitoring so you're alerted if any sub's license status changes mid-project.
What happens if a subcontractor's COI expires while they're working on my project?
If a subcontractor's Certificate of Insurance expires during a project and an incident occurs, you may be personally liable for damages that would otherwise have been covered by their policy. Depending on your prime contract, you may also be in breach of owner obligations if a sub works with a lapsed COI on your site. Set a calendar reminder 30 days before each sub's COI expiration date and require proof of renewal before they continue work. COI tracking software automates this so you don't rely on manual calendar management.
Is a subcontractor agreement legally required, or is a handshake deal enough?
An oral agreement is technically a contract in most states, but nearly impossible to enforce when a dispute arises — and disputes over scope, payment terms, and indemnification are common. Without a written agreement, you have no documented proof of scope of work, payment schedule, insurance requirements, or lien waiver obligations. Courts default to the sub's version of events in the absence of a written record. For any project above a nominal dollar amount, use a written agreement. AIA A401 or ConsensusDocs 750 are widely accepted standard forms.
Stop chasing documents manually
TrackMyVendor collects COIs, monitors license status, and tracks W-9s automatically — and alerts you before anything lapses. Your subcontractor onboarding checklist becomes a system, not a spreadsheet.
Related resources
Quick pre-work check: license, COI, W-9, and red flags
COI management guide for general contractors
Line-by-line review of what a valid COI must contain
Collect and track W-9 forms automatically — stay 1099-ready
Build a system that scales across your sub roster
7 documents to collect before any vendor starts work