Customer Asking for a W-9: What It Means and How to Fill It Out

When a customer asks you to fill out a W-9, they’re telling you they intend to treat you as an independent contractor and report what they pay you to the IRS. The form, officially the Request for Taxpayer Identification Number and Certification, collects your legal name, business type, and taxpayer identification number so your customer can issue a year-end 1099. Starting in tax year 2026, businesses must file a 1099 for non-employee payments of $2,000 or more, up from the longstanding $600 threshold.¹ If you’ve been paid anywhere near that, expect the request.

Why the Customer Needs It

Federal law requires businesses to track what they pay independent contractors, freelancers, and other non-employees. Once those payments reach the reporting threshold in a calendar year, the payer must file an information return with the IRS, typically a Form 1099-NEC for non-employee compensation or a Form 1099-MISC for rent and certain other payments.¹ The W-9 is how they collect the data to prepare it.

Most customers ask for the W-9 before they issue your first payment, because without it they can’t file accurately and face penalties of their own. The reporting obligation generally applies to payments made to individuals, sole proprietors, partnerships, and certain LLCs. Payments to C corporations and S corporations are usually exempt, which is why the form asks about your business type: your classification tells the customer whether they even need to file a 1099.¹

What It Says About Your Work Relationship

A W-9 means your customer is treating you as a contractor, not an employee. Employees fill out a different form entirely, the W-4, which tells the employer how much income tax to withhold from each paycheck.² As a contractor, no taxes come out of your payments. You’re responsible for setting aside money for both federal income tax and self-employment tax on your own, typically through quarterly estimated payments.

If you think you should be treated as an employee based on how the work is directed and controlled, the IRS lets you file Form SS-8 to ask for a formal determination of your worker status.³ Sorting that out early is easier than untangling it at tax time.

How to Fill It Out

The W-9 is one page. The classification lines cause more mistakes than anything else on it.

Your Name and Business Type

Line 1 asks for your legal name. If you’re a sole proprietor, this must match the name on your Social Security card. Any trade name or doing-business-as name goes on Line 2. Corporations and partnerships put their registered legal name on Line 1.⁴

Line 3 asks you to check a box for your federal tax classification. The main choices:

Individual or sole proprietor, which covers most freelancers and self-employed people.
C corporation or S corporation, for incorporated businesses.
Partnership, for multi-member partnerships.
LLC, where you also have to indicate how the LLC is taxed (as a C corporation, S corporation, or partnership). A single-member LLC that hasn’t elected corporate tax treatment is a disregarded entity and follows the individual/sole proprietor rules.⁴

The disregarded-entity LLC is where most people slip up. If you own a single-member LLC that hasn’t elected corporate taxation, your personal name goes on Line 1 and the LLC’s name on Line 2. You use your own Social Security Number as the TIN, even if the LLC has a separate EIN for payroll or banking.⁵

Taxpayer Identification Number

Which number belongs in Part I depends on your entity type:

Individuals and sole proprietors use their Social Security Number.⁴
Corporations, partnerships, and multi-member LLCs use the entity’s Employer Identification Number.
Non-citizens without an SSN use an Individual Taxpayer Identification Number, which the IRS issues to people who have a federal tax obligation but aren’t eligible for an SSN.⁶

Getting the TIN right matters. Your customer submits it to the IRS, which matches it against the name you provided. A mismatch can trigger backup withholding on your payments and penalties for your customer.

The Exemption Fields and Certification

Line 4 has two optional boxes: an exempt payee code and a FATCA exemption code. Most individual contractors and freelancers leave both blank. The exempt payee code applies mainly to corporations, government entities, tax-exempt organizations, and financial institutions. The FATCA field only matters for accounts held outside the United States at certain foreign financial institutions.⁵

The signature line is not optional. You’re certifying under penalty of perjury that your name, TIN, and classification are correct and that you’re not subject to backup withholding, or that you are if the IRS has already told you so. Don’t skip the date. An unsigned form will come right back to you.

Protecting Your Personal Information

Handing over your Social Security Number to anyone feels risky, and it should. Before you fill out a W-9, verify the request is legitimate. A real customer who owes you money for work already performed or contracted has a clear reason to ask. A stranger who emails you a W-9 request out of the blue does not.

The IRS warns businesses to watch for phishing attempts and recommends verifying any email request by calling the sender directly.⁷ The same advice runs in reverse. If a new client sends a W-9 request by email, pick up the phone and confirm before you reply with your SSN attached.

When you send the completed form, use a secure method. Password-protected and encrypted email is the minimum. Many companies provide a secure vendor portal for uploads. Avoid sending an unencrypted W-9 as a plain email attachment. Physical mail beats unprotected email if no digital option is available.⁷

One option that limits how widely your SSN circulates: apply for an EIN from the IRS. It’s free, takes minutes online, and you can use it on your W-9 in place of your Social Security Number.

What Happens If You Don’t Send It

Ignoring the request doesn’t stop your customer from paying you, but it does force them to start withholding. When a payer can’t get a valid TIN, they must deduct 24% of every payment and send it to the IRS. This is called backup withholding.⁸

Backup withholding also kicks in if the TIN you provide doesn’t match IRS records, or if the IRS has notified you that you’ve been underreporting income. The 24% applies to the gross payment before any expenses.⁹

The money isn’t gone forever. Withheld amounts credit your tax account and you claim them when you file. But collecting 76 cents on the dollar in the meantime is punishing for a small operation. To stop backup withholding, fix whatever triggered it, usually by sending a corrected W-9 with the right TIN and certification.⁸

Penalties for Getting It Wrong

The W-9 carries real consequences for inaccurate or false answers. The penalty depends on the nature of the mistake:

Failing to provide your TIN: a $50 penalty for each failure, unless you show reasonable cause.⁵
Making a false statement to avoid backup withholding: a $500 civil penalty if you claim an exemption without a reasonable basis.⁵
Willfully falsifying the form: because you sign under penalty of perjury, deliberate lies can lead to criminal penalties, including fines and imprisonment.⁵

Honest mistakes happen, and the IRS generally distinguishes a typo from fraud. Even so, check your TIN and classification before you sign.

When to Send a New W-9

The form doesn’t expire, but several changes require you to send an updated one to every customer holding a copy:

Your legal name changes through marriage, court order, or business restructuring.
Your TIN changes, such as switching from an SSN to an EIN.
Your tax classification changes, for instance if a C corporation elects S corporation status or you lose tax-exempt status.⁵
You previously claimed exempt payee status but no longer qualify.⁵

Some customers ask for a fresh W-9 every year or two as a matter of internal policy. That’s their compliance process, not an IRS rule, and it’s easier to comply than to argue.

What Comes Next: The 1099

After you send in the W-9, it sits in your customer’s files until year-end. They then use it to prepare a Form 1099-NEC reporting the total they paid you. Your copy should arrive by January 31 of the following year. A copy also goes to the IRS, linking the income to your TIN.¹⁰

The 1099 reports gross payments, not profit. You may have spent thousands on materials, software, or subcontractors to earn that income, but the form shows the full amount the customer paid. You claim your deductions on Schedule C when you file, which reduces the gross figure to taxable net income.

Because the IRS gets the same 1099 you do, any gap between what’s reported and what you show on your return will generate an automated notice. If a client overstates your income, catch it before you file. Contact the payer and ask for a corrected 1099 first; most will issue one once you point out the discrepancy.¹¹ If you can’t get a correction by the end of February, call the IRS at 800-829-1040 with your details and the amounts in question.

One Note on the New Threshold

The old $600 trigger is being replaced. Starting with tax year 2026, the 1099 filing threshold for non-employee payments jumps to $2,000, with inflation adjustments beginning in 2027.¹ Some smaller gigs won’t produce a 1099 at all under the new rule.

No 1099 doesn’t mean no tax. You owe income tax and self-employment tax on all earnings, whether or not a form is issued. The 1099 is a reporting tool for the payer; your obligation to report income exists on its own. Customers may still request a W-9 for smaller jobs because they can’t always predict the year-end total when the work begins.

1
Internal Revenue Service. 2026 Publication 1099 (Draft)
2
Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification
3
Internal Revenue Service. 1099-NEC and 1099-MISC Income Treatment Scenarios
4
Internal Revenue Service. Instructions for the Requester of Form W-9
5
Internal Revenue Service. Form W-9, Request for Taxpayer Identification Number and Certification
6
Internal Revenue Service. Individual Taxpayer Identification Number (ITIN)
7
Internal Revenue Service. Identity Theft Information for Businesses
8
Internal Revenue Service. Topic No. 307, Backup Withholding
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Internal Revenue Service. Fast Facts to Help Taxpayers Understand Backup Withholding
10
Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC
11
Internal Revenue Service. What to Do When a W-2 or Form 1099 Is Missing or Incorrect