What is a W-9, and how do you fill one out?
The first time a client says "can you send me a W-9?", it can feel like a test you didn't study for. It isn't. A W-9 is one of the simplest tax forms you'll ever handle — a short, one-page form that tells a payer who you are for tax purposes. This guide explains what it's for, walks through it line by line, covers the SSN-versus-EIN question, and shows how this little form connects to everything else in your tax year.
The plain-English version: a W-9 is how a client collects your legal name and taxpayer ID up front, so that after the year ends they can report what they paid you to the IRS on a 1099. You fill it out once per client and you're done.
What a W-9 actually is
The full name is Form W-9, "Request for Taxpayer Identification Number and Certification." It's an IRS form, but here's the key point that surprises people: you don't send it to the IRS. You send it to whoever asked for it. They keep it in their records and use it to fill out the information return — usually a 1099 — that reports your payments at year-end. The official IRS Form W-9 page is the primary source and has the current form and instructions.
All the W-9 does is collect four things about you: your legal name, your business name (if you use one), your federal tax classification (how your business is taxed), and your taxpayer identification number — either a Social Security Number (SSN) or an Employer Identification Number (EIN). Then you sign to certify the information is correct.
Who asks for a W-9, and why
Anyone who pays you in a way they may have to report to the IRS can ask for a W-9. The most common requesters are:
- Clients and companies that hire you as an independent contractor. If they pay you at or above the reporting threshold for the year, they'll issue you a 1099-NEC — and they need your W-9 to do it.
- Gig platforms and marketplaces — rideshare, delivery, freelance, and creator platforms — collect your taxpayer info so they can issue a 1099-NEC or 1099-K. If you drive or deliver, our gig worker taxes guide covers what those forms mean for you.
- Banks, brokerages, and other financial institutions, which may need to report interest, dividends, or other income tied to your taxpayer number.
In every case the logic is the same: the payer needs a verified name and taxpayer number so the amount they report to the IRS matches the person who received it. The W-9 is how they collect that once, cleanly.
How to fill out a W-9, line by line
The form is short. Here's what each part is asking, with the common freelancer case called out.
Line 1 — Name
Your legal name, as it appears on your tax return. For most freelancers that's simply your own name. This line must match the name that goes with the taxpayer number you'll enter later — a mismatch here is the single most common reason a W-9 gets bounced back.
Line 2 — Business name / disregarded entity name
Your business or "doing business as" (DBA) name, if it's different from Line 1. If you operate under your own name, leave this blank. A single-member LLC would put its LLC name here while still putting the owner's name on Line 1.
Line 3 — Federal tax classification
This is the box people hesitate on. You check one box describing how your business is taxed:
- Individual / sole proprietor or single-member LLC — the box most freelancers check. If you work for yourself and haven't formed a corporation or partnership, this is you. A single-member LLC that hasn't elected to be taxed as a corporation also checks this box (not the separate LLC box).
- C corporation, S corporation, or partnership — only if your business is actually organized and taxed that way.
- Limited liability company — for LLCs taxed as a corporation or partnership; you note the tax classification. A single-member LLC taxed as a sole proprietor does not use this — it uses the individual/sole proprietor box above.
If you genuinely don't know how your business is classified, that's worth a quick check with a tax professional before you sign.
Line 4 — Exemptions
Codes for entities exempt from backup withholding or FATCA reporting. Individuals and most freelancers leave this blank — it's aimed at certain organizations and financial entities, not everyday contractors.
Address
Your mailing address, so the requester can send you the 1099 (and any correspondence) at year-end. Use the address where you want tax documents to arrive.
Part I — Taxpayer Identification Number (TIN)
Here you enter one number: your SSN or your EIN. A sole proprietor can use either. This is where the SSN-versus-EIN decision matters — see the next section. Whatever you enter has to belong to the taxpayer named on Line 1.
Part II — Certification and signature
By signing, you certify that the taxpayer number is correct, that you're a U.S. person, and that you're not subject to backup withholding (with a narrow exception the instructions explain). Don't skip the signature — an unsigned W-9 is incomplete, and in some cases an unsigned or incorrect form can trigger backup withholding.
SSN or EIN? The number worth thinking about
If you're a sole proprietor, you can put your Social Security Number on the W-9 — but you don't have to. You can instead apply for a free Employer Identification Number (EIN) from the IRS and use that. An EIN is a business tax ID that works on the W-9 just like an SSN, and it means you're not handing your Social Security Number to every client who asks.
For freelancers who send out several W-9s a year, an EIN is a small, sensible privacy upgrade. You can apply directly and for free on the IRS EIN application page — be wary of third-party sites that charge for what the IRS provides at no cost.
What "backup withholding" means
The certification mentions backup withholding, and it sounds more alarming than it is. Normally a client pays you the full amount and you handle your own taxes. Backup withholding is the exception: if you don't provide a correct taxpayer number, or the IRS tells the payer your number is missing or wrong, the payer must hold back a flat percentage of your payments and send it to the IRS instead of to you.
The rate is a fixed percentage set by the IRS. For the vast majority of contractors who complete an accurate W-9 and sign it, backup withholding simply doesn't apply — which is one more reason to fill the form out carefully and get the name-and-number match right.
Send it safely — it's sensitive
A completed W-9 contains exactly the information someone would want in order to impersonate you: your name, address, and SSN or EIN. Treat it accordingly.
- Verify the requester first. Confirm you're actually doing business with them and that the request is legitimate before sending anything. Unsolicited W-9 requests are a known phishing tactic.
- Send it securely. Prefer an encrypted portal, a secure document service, or a password-protected file over plain email whenever you can. If a platform provides its own W-9 upload flow, use it.
- Keep a copy. Save your own signed copy so you can reuse the details next time and reconcile the 1099 you receive later.
How the W-9 fits into your tax year
The W-9 is small, but it starts a chain that runs through your whole tax season:
- You give a client or platform your W-9.
- After the year ends, they use it to issue you a 1099-NEC or 1099-K reporting what they paid you.
- That income flows onto your Schedule C, where you also subtract your 1099 tax deductions to arrive at your business profit.
- Your profit drives your self-employment tax and income tax — the numbers our self-employed tax calculator estimates for you.
- Because no tax was withheld from those payments, you generally cover the bill through quarterly estimated taxes across the year.
So the W-9 you sign in a few seconds is the front door to your whole self-employed tax picture. Knowing when your taxes are due and setting money aside as you're paid keeps the rest of the chain painless.
Frequently asked questions
Do I send my W-9 to the IRS?
No. You send it to whoever requested it — a client, a gig platform, or a bank — not to the IRS. They keep it on file and use it to prepare the 1099 they may issue you. Because it holds sensitive information, only send it to a payer you actually do business with.
What's the difference between a W-9 and a W-4?
A W-9 is for contractors: it gives a payer your taxpayer info so they can report your pay on a 1099, with nothing withheld. A W-4 is for employees: it tells an employer how much tax to withhold, reported later on a W-2. W-9 means contractor; W-4 means employee.
Can I use an EIN instead of my SSN on a W-9?
Often yes. A sole proprietor or single-member LLC can get a free EIN from the IRS and use it on the W-9 instead of an SSN — a common way to avoid sharing your Social Security Number with every client. The name on Line 1 still has to match the number's owner.
What is backup withholding?
It's when a payer holds back a flat, IRS-set percentage of your pay and sends it to the IRS, generally because a correct taxpayer number wasn't provided. For contractors who complete and sign an accurate W-9, it typically doesn't apply.
Which tax classification do I pick as a freelancer?
Most freelancers check "Individual/sole proprietor or single-member LLC" on Line 3. A single-member LLC that hasn't elected corporate treatment uses that box too. Only pick a corporation or partnership box if your business is actually taxed that way.