What is a Form W-9?
Updated · By Robert Breen
Form W-9 is a U.S. IRS form that a contractor or vendor fills out to give a business their legal name, tax classification and taxpayer identification number. Businesses collect it so they can file information returns, such as a 1099, for people and companies they pay.
Why it matters for a small business
If you pay contractors, you will usually need their W-9 information at year-end to file information returns. Asking in January, when the work is long done and the contractor is busy with their own taxes, is how firms end up chasing paperwork for weeks. Collecting the W-9 before the first payment avoids that.
A W-9 contains a taxpayer ID, often a Social Security number, so it is sensitive. It should travel through a secure portal and live in a protected file, not in email threads or AI chats. This page is general information, not tax advice. Rules change and depend on the payment and the payee, so have a CPA or enrolled agent confirm what you need to collect and file.
In a real lesson: Turn a Client Meeting into Action Items and a Follow-Up Email (Accounting Firms)
In the Summarize a Client Meeting lesson, Tom Alvarez of Millbrook Accounting, a made-up firm, flags a problem in the Q3 review with Cedar Lane Landscaping: "Three of the subcontractors still have no W-9 on file. Last January we were chasing them for weeks."
Maya Brooks turns it into a decision: get them now, not in January. The client's Jordan Pike agrees: "I'll have all three by the end of October." When ChatGPT builds the action items table from the transcript, that becomes a row with Jordan as owner and the end of October as the due date, and it shows up again in the follow-up email to the client.
Notice what never appears in the transcript or the prompt: anyone's taxpayer ID. The meeting talks about the forms, not their contents, which is exactly how it should be when the summary is going through an AI tool.
Try this lesson free or read the step-by-step guide.
Common confusions
W-9 vs 1099
The W-9 is what you collect from the contractor. A 1099 is the information return you may file, and send them a copy of, after the year ends. The W-9 provides the details the 1099 needs.
W-9 vs W-4
A W-4 is filled out by employees for payroll withholding. A W-9 is for contractors and vendors who are not on payroll. Whether someone is an employee or a contractor is a legal question worth asking a professional.
Tips
- Make a W-9 part of onboarding every new contractor, before the first payment.
- Collect forms through a secure portal, never by plain email or text.
- Track who has and hasn't returned one in a simple list with names only, no ID numbers.
Related terms
Where you use it: free lessons
Frequently asked questions
- When should I ask a contractor for a W-9?
- Ideally before you pay them for the first time. It is much easier than chasing forms at year-end, as the lesson's firm learned.
- Can I use ChatGPT to fill out or check a W-9?
- Don't paste taxpayer IDs into an AI chat. Ask your CPA or enrolled agent about anything on the form you are unsure of.