Collect a W-9 and COI from Subcontractors Before the First Payment
The two documents accounting asks for most often are the two that are easiest to forget until the first invoice lands: the W-9 for tax reporting and the certificate of insurance that proves the sub is covered. Ask for both before anyone is paid, check that they describe the same company, and you avoid the year-end 1099 scramble and paying a sub with no coverage.
Before the first payment, get a signed Form W-9 and a current certificate of insurance from every subcontractor, and check that the W-9 legal name, the COI named insured and the subcontract party are the same entity. The W-9 supports 1099-NEC reporting (at least $2,000 paid in a year, for tax years after 2025) and avoids 24% backup withholding. The COI proves coverage for the dates you are paying for.
Key Takeaways
- Make a W-9 and a current COI conditions of the first payment, not of year-end.
- Three names must match: W-9 legal name, COI named insured, subcontract party.
- Collect a W-9 even from corporations; it tells you whether 1099 reporting applies.
- Re-check the COI before each payment, because policies can lapse mid-project.
1. Why Before the First Payment
Before you pay, the subcontractor wants something from you, so paperwork comes back quickly. After the first check clears, the same request can take weeks. Both documents also protect you from costs that land later:
- Tax reporting. The IRS instructions for tax years after 2025 call for a Form 1099-NEC for each person you paid at least $2,000 during the year for services (IRS instructions for Forms 1099-MISC and 1099-NEC). You need the name and TIN from the W-9 to file it.
- Backup withholding. If a payee who should give you a TIN does not, you may have to withhold 24% from reportable payments (IRS: backup withholding). A W-9 on file before the first payment keeps you out of that.
- Insurance audits.At your workers' compensation and general liability audits, payments to subs who could not show coverage for the period are often added to your own payroll basis. Our uninsured subcontractor audit formula shows how that is calculated.
2. What to Check on Each Document
Receiving the documents is not the same as checking them. Five checks catch almost every problem:
| Check | On the W-9 | On the COI |
|---|---|---|
| Name | Legal name on line 1 (and business name on line 2 if different). | Named insured matches the W-9 legal name, not just a trade name. |
| Entity | Federal tax classification box checked (individual, LLC and its tax class, corporation, partnership). | The same entity holds the policies. A parent or sister company is not the same insured. |
| Identifier | TIN present, in the right format (SSN or EIN), and consistent with the entity type. | Policy numbers and insurers listed for every coverage your contract requires. |
| Dates | Signed and dated. Current form revision. | Effective dates cover the work dates, including the first payment period. |
| Requirements | Exempt payee code, if claimed, makes sense for the entity. | Limits meet your minimums; additional insured, waiver and primary wording backed by endorsements. |
If you file 1099s, the IRS TIN Matching program, available to authorized payers through IRS e-Services, lets you confirm a name and TIN combination before year-end. For the certificate, our guide on spotting a fake certificate of insurance covers verifying with the producer.
3. The Name-Match Problem
The most common mismatch is a sub that operates under a trade name or has more than one company. The W-9 says "Rivera Holdings LLC", the COI says "Rivera Electric", and the subcontract says "Rivera Electrical Services Inc." Those may be three different legal entities, and the insurance only covers the one named on the policy.
When the names differ, ask which entity signed the subcontract and is doing the work, and have the broker confirm that entity is a named insured. Fix the subcontract or the certificate before paying, not after a claim.
4. A Four-Step Process
- Request both together in the onboarding packet, with your insurance requirements attached so the broker gets them right the first time.
- Check them together against the table above, and reject with a specific reason when something is off.
- Record expiration dates for every policy, and ask for the renewal certificate about 60 days before it lapses.
- Gate the payment. Agree with accounting that an invoice from a sub missing either document does not get scheduled.
5. Doing It in SubDoc
- Add a W-9 to the requirement template (the property management, facilities and commercial real estate templates already include one), and every new vendor is asked for it with their insurance.
- The vendor uploads both from one link with no account, and can forward it to their broker for the certificate.
- SubDoc reads the certificate, checks limits and endorsements against your requirements, and your team approves it.
- A vendor missing a required document stays non-compliant, and an invoice from a non-compliant vendor cannot be scheduled for payment.
Tax rules change. This guide summarizes IRS guidance current as of October 2026 and is not tax advice. Confirm your reporting obligations with your accountant.
Frequently Asked Questions
Collect one anyway. Payments to corporations are generally not reported on Form 1099-NEC, but there are exceptions, such as payments for legal services, and the W-9 is how you learn the subcontractor's entity type in the first place. It also gives you a certified taxpayer identification number on file.
If a payee who should provide a taxpayer identification number does not, the IRS backup withholding rules can require you to withhold 24% from reportable payments and send it to the IRS. Most GCs avoid the problem entirely by making a completed W-9 a condition of the first payment.
For tax years after 2025, the IRS instructions say to file Form 1099-NEC for each person you paid at least $2,000 during the year for services in your trade or business. Earlier years used a $600 threshold. Check the current IRS instructions for Forms 1099-MISC and 1099-NEC each year.
Yes. The legal name on the W-9, the named insured on the certificate of insurance and the party on the subcontract should be the same entity. If the COI names a different company, the policy may not cover the business you hired.
When the subcontractor's legal name, business structure, address or tax ID changes, or if the IRS sends you a notice that a name and TIN do not match. Insurance certificates need renewing at every policy renewal, which is usually yearly.
Related Guides
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