A W-9 form is the IRS form a US business uses to collect your correct name and taxpayer identification number (your SSN or EIN) so it can report what it pays you. You fill it in, sign it and give it to the business that asked; you don't send it to the IRS.
If a new client has just emailed you a W-9 before your first invoice, nothing is wrong. It's the paperwork they need so they can file an information return, usually a 1099, at the end of the year. The current version is Form W-9 (Rev. March 2024), and the IRS says on the form itself: give the form to the requester and don't send it to the IRS.
Who asks for a W-9, and why
The IRS describes Form W-9 as the way you give your correct TIN to the person who has to file an information return about you. Its own examples of what those returns report are:
- Income paid to you
- Real estate transactions
- Mortgage interest you paid
- Acquisition or abandonment of secured property
- Cancellation of debt
- Contributions you made to an IRA
For freelancers, consultants and small agencies, the first one is the reason you'll see it most. A client that pays you as a contractor rather than an employee asks for a W-9 so the name and number on their year end paperwork match the IRS records. If you're still working out which side of that line you sit on, my guide to 1099 contractors versus W-2 employees walks through the difference.
Every line of the W-9, in plain English
| Line | What goes there | The catch |
|---|---|---|
| Line 1 | Your name, or your entity's name | Sole proprietors and disregarded entities put the owner's name here, not the business name |
| Line 2 | Business, trade or DBA name | Only if it's different from line 1 |
| Line 3a | Federal tax classification | An LLC that isn't disregarded checks the LLC box and writes C, S or P for how it's taxed |
| Line 3b | Foreign partners, owners or beneficiaries | New in the March 2024 version; only for flow-through entities such as partnerships |
| Line 4 | Exempt payee code and FATCA code | Most freelancers and sole traders leave this blank |
| Lines 5 and 6 | Your address | Where the requester will mail your information return |
| Part I | Your TIN: SSN or EIN | It must match the name on line 1, or you risk backup withholding |
| Part II | Signature and date | You certify under penalties of perjury that the details are correct |
The line that trips people up most is line 1. The IRS instructions say a sole proprietor enters their individual name as shown on their Form 1040 on line 1, and their business, trade or DBA name on line 2. Put your trading name on line 1 instead and the name and number won't match, which is exactly what the form exists to prevent.
SSN or EIN: which number do you give?
For individuals, the form says the TIN is generally your social security number. Other entities use an employer identification number. A single member LLC that's treated as a disregarded entity gives the owner's details: the owner's name on line 1, the LLC's name on line 2, and the classification box for the owner on line 3a. The IRS added that clarification for disregarded LLCs in the 2024 revision.
If you'd rather not hand your SSN to every client, many sole proprietors get an EIN and use that instead. My walkthrough on getting an EIN for a small business covers the free IRS route. And if you don't have a number yet, the form lets you write Applied For in the TIN space once you've applied, then sign and date it.
What happens if you don't return it
This is the insight most people miss. If you don't give the requester a correct TIN, or you don't sign the certification where it's required, the payer has to start backup withholding: holding back nearly a quarter of each reportable payment and sending it to the IRS. The requester's instructions say that applies until the cause is fixed, and a payer who should have withheld and didn't can become liable for the uncollected amount. So a client chasing your W-9 isn't being fussy; they're protecting themselves.
The form also lists the penalties on your side, as of October 2026:
| Problem | Penalty stated on Form W-9 |
|---|---|
| Failing to give your correct TIN | $50 for each failure, unless it's due to reasonable cause and not willful neglect |
| A false statement with no reasonable basis that results in no backup withholding | $500 |
| Willfully falsifying certifications | Criminal penalties, including fines and/or imprisonment |
How to fill in and send a W-9 safely
- Download the current Form W-9 from irs.gov, or use the requester's own version if they send one (the IRS says US persons must use the requester's form if it's substantially similar).
- Enter your name on line 1 exactly as it appears on your tax return, and any business name on line 2.
- Tick one box on line 3a for your tax classification, and leave line 3b alone unless you're a partnership or trust with foreign owners.
- Add your address, then your SSN or EIN in Part I.
- Sign and date Part II.
- Return it to the requester, never to the IRS, using a secure method rather than a plain email attachment.
The last step matters because the form carries your tax number. The requester's instructions say businesses can set up a system to collect W-9s electronically, as long as it ends with an electronic signature under penalties of perjury. If a client offers a secure portal, use it. And the form warns that a requester who misuses or discloses TINs in breach of federal law can face civil and criminal penalties.
If you're outside the US
Form W-9 is for US persons. The requester's instructions tell businesses to point foreign persons to the right Form W-8 instead, or Form 8233 for some individual services. So if you're a UK, Canadian or Australian freelancer and a US client sends you a W-9, reply and ask which W-8 they need. Filling in a W-9 when you're not a US person is the wrong form, not a shortcut.
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My verdict
A W-9 takes five minutes and saves you a fight later. Fill it in the day it arrives, make sure line 1 matches your tax return, use an EIN if you don't want your SSN sitting in a client's inbox, and keep a signed copy for yourself. If you're not a US person, don't sign it at all: ask for the W-8 instead.
Frequently asked questions
What is a W-9 form used for?
Form W-9 is used to give your correct taxpayer identification number to a person or business that has to file an information return with the IRS about payments to you, such as income paid to you as a contractor.
Do I send my W-9 to the IRS?
No. The form itself tells you to give it to the requester and not to send it to the IRS.
Do I put my business name on line 1 of a W-9?
Not as a sole proprietor. The IRS says sole proprietors enter their individual name on line 1 and their business, trade or DBA name on line 2.
Can I use an EIN instead of my SSN on a W-9?
The form says individuals generally use their social security number and other entities use an EIN. Many sole proprietors apply for an EIN so they don't have to share their SSN; check the IRS instructions for Part I for your situation.
What happens if I don't fill out a W-9?
If you don't give a correct TIN or sign where required, the payer may have to apply backup withholding to your payments, and the form says you can face a $50 penalty for each failure to furnish your correct TIN.
Which version of Form W-9 is current?
The IRS page lists Form W-9 (Rev. March 2024) as the current revision, with no recent developments listed when checked in October 2026.
I'm not a US person. Should I fill out a W-9?
No. The IRS tells requesters to give foreign persons the appropriate Form W-8 or Form 8233 instead of Form W-9.
