How to Fill Out a W-9 (Line-by-Line Guide for 2026)
🔒 Key point: a W-9 is given to the business that asked for it, not filed with the IRS. Because it carries your SSN or EIN, only ever send it to a payer you trust, over a secure channel.
- A W-9 gives your Taxpayer Identification Number (TIN) to a business that needs to report payments it makes to you.
- It's usually requested from independent contractors, freelancers and vendors before they're paid.
- The form is short: your name, tax classification, address and TIN (SSN or EIN), then a signature.
- Get it wrong or refuse to provide it, and the payer must apply 24% backup withholding to your payments.
- You give the W-9 to the requester and keep a copy — it's never sent to the IRS.
- Need an EIN to put on your W-9? We can sort that.
If a client has asked you to "send over a W-9," don't overthink it — it's one of the simplest IRS forms, and you can usually complete it in a couple of minutes. It exists so the business paying you can report that income correctly. This guide walks through the W-9 line by line, explains backup withholding, and clears up how it differs from the other forms it's often confused with.
What is a W-9 form?
Form W-9, Request for Taxpayer Identification Number and Certification, is how you give your correct TIN to a person or business that has to file an information return about payments made to you — most commonly a 1099.
In plain terms: a client is going to pay you, and at tax time they'll report those payments to the IRS. To do that, they need your correct name and tax number on file. The W-9 is simply how they collect it. You fill it out once, hand it back, and they keep it in their records.
Who needs to fill out a W-9?
You'll be asked for a W-9 if you're a US person receiving reportable payments as something other than an employee. That typically means:
- Independent contractors and freelancers starting work with a new client
- Vendors and suppliers a business pays
- Consultants, gig workers and single-member LLC owners
- People opening an interest- or dividend-earning account, or involved in certain property transactions
One important exception: the W-9 is for US persons — US citizens, resident aliens and US entities. If you're a non-US person, you complete a W-8 form instead, not a W-9.
How to fill out a W-9, line by line
Here's exactly what goes in each part of the form:
| Line | What to enter |
|---|---|
| Line 1 — Name | Your name exactly as it appears on your tax return. Never leave this blank. |
| Line 2 — Business name | Your business or trade name, only if it's different from Line 1. Otherwise leave blank. |
| Line 3 — Tax classification | Tick one box: individual/sole proprietor, C corporation, S corporation, partnership, trust/estate, or LLC (with its tax type). |
| Line 4 — Exemptions | Usually left blank. Only certain exempt payees and FATCA cases enter a code here. |
| Lines 5–6 — Address | Your street address, city, state and ZIP — where the payer will send your 1099. |
| Line 7 — Account numbers | Optional. Only if the requester asked you to list specific account numbers. |
| Part I — TIN | Your SSN if you're an individual or sole proprietor, or your EIN if you have one for your business. |
| Part II — Certification | Sign and date to certify the details are correct and that you're not subject to backup withholding. |
If you run a business and would rather not hand out your personal SSN, you can put an EIN in Part I instead. Many sole proprietors get an EIN purely for this reason — our EIN registration service can obtain one for you.
What is backup withholding?
Backup withholding is the reason a W-9 matters. If you don't give a correct TIN, or the IRS has notified the payer that you underreported interest or dividends, the payer must withhold 24% of your payments and send it straight to the IRS.
That's a big chunk of your money tied up until you sort out your tax return. Completing the W-9 correctly — right name, right TIN, signed — is what keeps you out of backup withholding and ensures you're paid in full.
W-9 vs W-4 vs 1099
These three forms are constantly mixed up. Here's how they differ:
| Form | Who uses it | Purpose |
|---|---|---|
| W-9 | Contractors & vendors | Give your TIN to a payer |
| W-4 | Employees | Set tax withholding from wages |
| 1099 | Payers | Report what they paid you |
In short: a W-4 is for employees, a W-9 is for contractors, and the 1099 is the form your client later files using the information from your W-9. If you'd like the full picture on the form your W-9 feeds into, see our guide to what a 1099 form is.
Do you send a W-9 to the IRS?
No. This is the most common misconception. You give the completed W-9 to the business that requested it — they keep it on file to prepare your 1099. It never goes to the IRS.
Because the form contains your SSN or EIN, treat it carefully: only send it to a legitimate payer you're actually working with, use a secure method rather than plain email where possible, and be wary of anyone requesting a W-9 out of the blue — it's a common phishing tactic. If in doubt about a request, our US tax team can advise.
Frequently asked questions
What is a W-9 form used for?
It provides your Taxpayer Identification Number to a business that pays you, so it can report those payments to the IRS — usually on a 1099. It's most often requested from independent contractors and vendors before they're paid.
Do I put my SSN or EIN on a W-9?
Either works. Individuals and sole proprietors can use their SSN, but if you have an EIN for your business you can use that instead — a good way to avoid sharing your personal Social Security Number with clients.
What happens if I don't fill out a W-9?
The payer is required to apply 24% backup withholding to your payments, sending that portion to the IRS instead of to you. Providing a correct, signed W-9 avoids this and gets you paid in full.
Is a W-9 the same as a 1099?
No. You fill out a W-9 to give your details to a payer; the payer then uses that information to file a 1099 reporting what they paid you. The W-9 comes first, the 1099 comes at year end.
Do I send my W-9 to the IRS?
No. You give it only to the business that requested it, and they keep it on file. Because it contains your SSN or EIN, send it securely and only to payers you genuinely work with.
We'll get you an EIN so you needn't share your SSN, keep your 1099 income organised, and file your return correctly. Fixed fee, no hassle. Get a quote or message us today.
Related: our US EIN registration service, US tax filing service, and guide to 1099 forms. Official guidance is on the IRS Form W-9 page.
