Definition
Form W-9 is the IRS form a US business asks a contractor or vendor to complete so it has their legal name, business type, address, and taxpayer identification number. The business keeps the form on file and uses the details to prepare Form 1099-NEC or other information returns. It is not sent to the IRS.
Also called: W-9, Request for Taxpayer Identification Number
Form W-9 in practice
Clients usually request a W-9 before paying a new contractor for the first time. Many accounts payable teams will not release payment until they have one on file, so sending it promptly avoids delays on your first invoice.
On the form you give either your Social Security number or your EIN, and certify that it is correct. Sole proprietors can use either; using an EIN keeps your SSN off documents that circulate through other companies.
If you do not provide a correct taxpayer identification number, the payer may be required to apply backup withholding to your payments and send it to the IRS.
Example
Before paying a new web developer's first invoice, a client's accounts team emails a blank Form W-9. The developer fills in her LLC name and EIN, signs it, and returns it the same day.
Frequently Asked Questions
Is it safe to send a W-9 by email?
The form contains your taxpayer ID, so use a secure upload portal or encrypted email when possible, and confirm the request is genuinely from your client before sending.
Do foreign contractors fill out a W-9?
No. W-9 is for US persons. Foreign individuals usually complete Form W-8BEN, and foreign entities Form W-8BEN-E, instead.
Related terms
- Form 1099-NEC Form 1099-NEC is the IRS information return a US business files to report payments for services made to an independent contractor or other non-employee during the year.
- EIN An EIN, or Employer Identification Number, is a nine-digit number the IRS assigns to a business to identify it for federal tax purposes in the United States.
- Tax ID A tax ID is the number a tax authority assigns to a business for reporting and collecting taxes.
- Withholding tax Withholding tax is an amount a client deducts from an invoice payment and pays directly to the tax authority on the supplier's behalf.
This page is for general information only and is not legal, tax, or financial advice. Rules change and vary by location, so consult a qualified lawyer or accountant about your situation.