The W-9 is the most basic vendor document, and it is the one that causes the most end-of-year problems when it was not collected correctly, or at all.
This guide explains the records, checks, and follow-up needed for reliable W-9 collection.
When You Are Required to Collect a W-9
Use Form W-9 to request the correct TIN and certifications of a U.S. payee when you need them for an information return. For payments made in 2026, the federal Form 1099-NEC reporting threshold for nonemployee compensation is $2,000. Other information returns, payment categories, backup-withholding cases, exceptions, and future inflation adjustments can use different thresholds, so check the current IRS instructions.
Corporations (C-corps and S-corps) are generally exempt from 1099 reporting, but you should still collect a W-9 to document the exemption.
The W-9 supplies information used for Forms 1099 and backup-withholding determinations. If a payee fails to furnish a TIN for reportable nonemployee compensation, the payer generally must backup withhold 24% from reportable payments and deposit it with the IRS.
Collect the W-9 before the first payment. Not after.
What Is on a W-9
The W-9 (Request for Taxpayer Identification Number and Certification) collects:
- Name: the individual's legal name or the business name
- Business name / DBA: if different from the legal name
- Federal tax classification: individual/sole proprietor, LLC (with tax treatment), C-corp, S-corp, partnership, trust, or other
- Address: used for mailing the 1099 at year end
- TIN: either a Social Security Number (for individuals) or Employer Identification Number (for businesses)
- Signature and date: certifying the information is correct
What to Verify on Every W-9
Use the correct name/TIN combination. If information returns contain missing or apparently incorrect name/TIN combinations, the IRS may issue CP2100 or CP2100A notices. The payer must then follow the applicable B-notice and backup-withholding procedure.
Eligible payers and authorized agents can apply to use the IRS TIN Matching Program before filing information returns.
Tax classification should be complete. It is one input to information-reporting decisions, together with the type of payment and applicable exceptions.
Determine whether certification is required. The IRS instructions identify when a signature is required; some Forms W-9 are not required to be signed. When certification is required, retain the signed and dated form or compliant electronic record.
Address must be legible and complete. You will use this to mail the 1099 if you do not have an email address for the vendor.
Common W-9 Mistakes
Accepting a W-9 with a Social Security Number from a business entity. If the form says "LLC" but the TIN is formatted like an SSN (XXX-XX-XXXX), verify whether the LLC is a single-member LLC treated as a disregarded entity. This is actually allowed, but you need to understand which type of entity you are working with.
Not getting an updated W-9 when information changes. If a vendor changes their name, entity type, or TIN, you need a new W-9. Request updates whenever you have reason to believe the information may have changed.
Storing W-9s insecurely. W-9s can contain Social Security Numbers or EINs. Apply risk-based safeguards such as encryption and least-privilege access, and avoid broadly accessible shared storage.
How Long to Keep W-9s
The Form W-9 instructions do not provide one universal retention period for every requester and use. Keep the form and related information-return support for as long as needed under the applicable federal recordkeeping rule, state law, contract, audit, and litigation-hold requirements. Our document retention guide explains how to set a defensible schedule.
What Happens If You Do Not Collect a W-9
If a payee does not provide a TIN for reportable nonemployee compensation, or another backup-withholding trigger applies, the payer generally must withhold 24% from reportable payments and follow IRS deposit and reporting rules. Document requests and use the current IRS instructions.
Making W-9 Collection Systematic
The operational goal is to make W-9 collection a mandatory step before any vendor is activated in your payment system, not an afterthought when 1099 season arrives in January. The finance team's guide to vendor payment compliance covers the payment-side controls this feeds.
A vendor compliance platform enforces this at onboarding: the vendor cannot be cleared for payment until a valid W-9 is on file. The platform validates that required fields are present and stores the form securely with access controls appropriate for tax identification data.