What Is a W-9 Form: How to Fill It Out and Backup Withholding

A W-9 form is a one-page IRS document that a business uses to collect your legal name, address, and taxpayer identification number so it can report any payments it makes to you on a Form 1099 at year’s end. The form stays with the payer and is never filed with the IRS. If you’re a freelancer, independent contractor, consultant, landlord, or anyone else earning money outside a traditional paycheck, you’ve almost certainly been handed one before your first payment arrives.

Who Has to Fill One Out

The W-9 is for U.S. persons who receive payments outside of an employer-employee relationship. Employees fill out a W-4 instead, which tells an employer how much tax to withhold from each paycheck. The W-9 goes to independent contractors, freelancers, consultants, and other non-payroll workers.¹

The reach of the form is broader than contract work alone. Banks and brokerages request it when you open an account that will earn interest or dividends. Real estate closings, debt cancellations, and IRA contributions can also trigger a W-9 request because the payer needs your TIN to file the correct information return.²

Most contractors see a W-9 request when a business expects to pay them at least $600 in a calendar year, since that’s the threshold for filing a Form 1099-NEC for nonemployee compensation.³ Many businesses ask for one before the first payment regardless of the amount they expect to pay, simply because chasing down TINs in January is painful.

If you’re a foreign individual or entity receiving U.S.-sourced income, the W-9 is not your form. You provide Form W-8BEN instead, which the payer uses to determine whether to withhold U.S. tax and at what treaty rate.⁴

How to Complete the Form

The W-9 is a single page, but a handful of lines trip people up, especially anyone operating through an LLC.

Lines 1 and 2: Your Name and Business Name

Line 1 asks for the name shown on your tax return. For individuals, that’s your legal name. Line 2 is optional and holds a business name, trade name, or “doing business as” name when it’s different from Line 1.²

Here’s where single-member LLC owners most often get it wrong. The IRS treats a single-member LLC as a “disregarded entity,” meaning it doesn’t exist separately from you for tax purposes. Put your own legal name on Line 1 and the LLC’s name on Line 2, not the other way around. A mismatch here causes problems with IRS records down the road.⁵

Line 3: Federal Tax Classification

Check one box for your entity type: individual or sole proprietor, C corporation, S corporation, partnership, trust or estate, or LLC.⁵

If you check the LLC box, you also have to write in the letter that matches your tax classification: C for C corporation, S for S corporation, or P for partnership. A multi-member LLC that hasn’t elected corporate status writes “P” because the IRS treats it as a partnership by default. An LLC taxed as a corporation checks the LLC box and writes “C” or “S” based on its election. What matters is how the IRS taxes the entity, not how your state classified the filing.⁵

Line 4: Exempt Payee Codes

Line 4 is reserved for entities exempt from backup withholding. Individuals and sole proprietors generally cannot claim an exemption. Eligible entities include tax-exempt organizations, government agencies, corporations (for certain payment types like interest and dividends), registered securities dealers, banks, and real estate investment trusts, among others. If an exemption applies, enter the matching numeric code; otherwise leave it blank.⁶

Part I: Taxpayer Identification Number

Your TIN is what links the form to your tax records. For most individual contractors it’s your Social Security number. Resident aliens without an SSN use an Individual Taxpayer Identification Number (ITIN).⁶ Corporations, partnerships, and multi-member LLCs provide their Employer Identification Number.

The 2026 revision of the W-9 spells out a point that has long tripped up small business owners: sole proprietors must use their SSN, and single-member LLCs treated as disregarded entities must use the owner’s TIN, not the entity’s EIN, even if the business has one.⁷ If the name and TIN you enter don’t match IRS records, the payer gets a notice and you can end up with backup withholding on future payments.

Part II: Certification

Part II is where you sign under penalty of perjury. By signing, you confirm four things: your TIN is correct, you’re a U.S. person, you’re not subject to backup withholding for underreporting interest or dividends, and you’re compliant with (or exempt from) the Foreign Account Tax Compliance Act (FATCA).²

If the IRS has already notified you that you’re subject to backup withholding because of underreported interest or dividend income, cross out the second certification item before signing. That tells the payer to start withholding 24% from your payments immediately, which is what the IRS expects.²

The 2026 revision adds a fifth certification checkbox for U.S. digital asset brokers. A qualifying broker exempt from information reporting under the applicable regulations can check this box to claim that status.⁷ It won’t apply to most people, but it’s a meaningful change for cryptocurrency businesses.

Backup Withholding: What Triggers It

When the W-9 process breaks down, the payer must start backup withholding. That means 24% of every payment to you goes straight to the IRS instead of into your pocket.⁸ Federal law sets out the specific triggers:⁹

You fail to furnish your TIN to the payer.
The IRS notifies the payer that the TIN you gave doesn’t match its records.
The IRS notifies the payer to begin withholding because you underreported interest or dividend income. This happens only after the IRS has sent you at least four notices over a 120-day period.
You fail to certify that you’re not subject to backup withholding.

The withheld 24% isn’t lost. It shows up as a credit on your tax return the same way any other withholding does. But losing a quarter of each check while you untangle the problem is a cash flow hit most freelancers can’t absorb. Fill out the form carefully the first time and the issue never arises.

When to Submit an Updated W-9

A completed W-9 doesn’t expire. No IRS rule requires you to resubmit it on any set schedule. It becomes invalid the moment the information on it stops being correct.¹⁰ Send your payers a fresh form when:

Your name changes through marriage, divorce, or a legal name change.
Your TIN changes, such as when you get an EIN for a newly formed partnership that previously operated under your SSN.
Your tax classification changes, such as a C corporation electing S corporation status, or a tax-exempt entity losing its exemption.
A grantor trust changes ownership (for example, when the grantor dies and the trust’s tax reporting shifts).

The IRS instructions don’t name a specific deadline. In practice, send the updated form before the next payment. If the payer issues a 1099 using stale information and the TIN doesn’t match, backup withholding and IRS notices follow.⁷ Some businesses ask every vendor for a fresh W-9 each year as a precaution. That’s allowed, even though the rules don’t require it.

Penalties for Getting It Wrong

If you fail to provide a correct TIN when required, the IRS can impose a $50 penalty for each failure, up to $100,000 per calendar year.¹¹ That’s on top of the 24% backup withholding the payer must apply once your TIN is known to be missing or incorrect.¹²

Deliberately lying on a W-9 is a different matter. Because you sign under penalty of perjury, willfully providing false TIN or tax status information can trigger criminal prosecution, with a maximum punishment of a fine up to $250,000 for individuals and three years in prison.¹³ Prosecutions for ordinary mistakes are extremely rare, but the form carries real legal weight.

Protecting the Information on Your W-9

A completed W-9 contains your name, address, and either your Social Security number or EIN. That’s essentially everything an identity thief needs. Handle a filled-out form the way you’d handle a copy of your Social Security card.

Don’t email an unencrypted W-9. The IRS allows electronic submission, but any system used to collect the form must verify the signer’s identity, encrypt the transmission, and include an electronic signature under penalty of perjury.¹⁰ A secure portal or encrypted upload is fine. If a business asks you to send the form as an unprotected PDF attachment, push back and ask for a safer option.

Be skeptical of unsolicited W-9 requests. A legitimate payer asks for one when they’re about to pay you for work, services, or another reportable transaction. A W-9 request from a company you’ve never done business with is a red flag, and the IRS asks taxpayers to report suspicious tax-related messages that may be phishing attempts.¹⁴ When something feels off, verify the request through a phone number or website you look up yourself, not through any link in the message.

1
Internal Revenue Service. Forms and Associated Taxes for Independent Contractors
2
Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification
3
Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC (04/2025)
4
Internal Revenue Service. About Form W-8 BEN, Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting (Individuals)
5
IRS. Instructions for the Requester of Form W-9 (Rev. March 2024)
6
IRS. Form W-9 (Rev. March 2024)
7
IRS. Form W-9 (Rev. January 2026)
8
Internal Revenue Service. Topic No. 307, Backup Withholding
9
Office of the Law Revision Counsel. 26 U.S. Code 3406 – Backup Withholding
10
Internal Revenue Service. Instructions for the Requester of Form W-9 (03/2024)
11
Office of the Law Revision Counsel. 26 USC 6723 – Failure to Comply With Other Information Reporting Requirements
12
Internal Revenue Service. Backup Withholding
13
Internal Revenue Service. Criminal Statutory Provisions and Common Law
14
Internal Revenue Service. Report Fake IRS, Treasury or Tax-Related Emails and Messages