How to Fill Out a W-9 Form: Lines, TIN, and Certification

Form W-9 is a one-page IRS form you complete so a client, bank, or other payer can collect your taxpayer identification number and report what they pay you. To fill out a W-9 form, enter your legal name on Line 1, add a business name on Line 2 only if it differs, check one tax classification box on Line 3, leave Line 4 blank unless you’re an exempt entity, put your mailing address on Lines 5 and 6, enter your SSN or EIN in Part I, and sign and date Part II. Then hand it to whoever asked for it. You never send a W-9 to the IRS yourself.¹

You’ll usually be asked for one when you take on freelance or contract work, open an interest-bearing account, close a real estate deal, or have a debt canceled.

Line 1: Your Legal Name

Write your name exactly as it appears on your federal income tax return. For an individual, that’s your legal first and last name. For a corporation or partnership, use the entity’s legal name as registered with the IRS. A name that doesn’t match the taxpayer identification number you enter in Part I is the fastest way to trigger an automated mismatch notice.¹

One trap catches people constantly. If you own a single-member LLC that’s treated as a disregarded entity for tax purposes, put your own name on Line 1, not the LLC’s name. The LLC name goes on Line 2. The IRS is explicit about this.²

Line 2: Business Name or DBA

Line 2 is for a trade name, “doing business as” name, or disregarded entity name that differs from Line 1. If you’re a sole proprietor operating under your own legal name with no separate business identity, leave it blank.¹

Line 3: Federal Tax Classification

Check exactly one box. Your choices:

Individual or sole proprietor. Use this if you file as an individual or run an unincorporated one-person business. A single-member LLC that’s disregarded for tax purposes also checks this box.
C corporation or S corporation. These are separate boxes; pick the one matching your corporate election.
Partnership.
Trust or estate.
LLC that isn’t disregarded. Check the LLC box and enter a single letter in the space next to it: C for C corporation, S for S corporation, or P for partnership. That letter tells the payer how your LLC is taxed federally.

The box you check controls how the payer reports the income, so make sure it matches your actual filing status.¹

Line 4: Exemption Codes

Most individuals leave Line 4 completely blank. It applies only to certain entities exempt from backup withholding, FATCA reporting, or both. Regular freelancers and independent contractors skip it. Unless a tax advisor has told you a specific exempt payee code applies to you, leaving both spaces empty is correct.³

Lines 5 and 6: Your Address

Line 5 is your street address, including any apartment or suite number. Line 6 is your city, state, and ZIP. This is where your 1099 forms will be mailed at the end of the year, so use an address where you reliably receive mail. If you move, send an updated W-9.¹

Part I: Your Taxpayer Identification Number

Part I has two rows of boxes: one for a Social Security Number, one for an Employer Identification Number. Enter one, not both. Most individuals and sole proprietors use their SSN. Partnerships and corporations use their EIN.⁴

A resident alien who doesn’t have and isn’t eligible for a Social Security Number enters an Individual Taxpayer Identification Number in the SSN boxes. Use the same name that appears on your Form W-7 application.¹

For a single-member LLC that’s disregarded, enter the owner’s SSN or ITIN, not the LLC’s EIN. The IRS treats a disregarded LLC as inseparable from its owner for tax purposes, so the owner’s number is what links the payment to the right account.²

Write clearly. Illegible digits or digits in the wrong boxes can lead the payer to report a mismatched TIN, and that carries a $50 penalty under IRC 6723 plus backup withholding on future payments until you fix it.⁵

Part II: Certification and Signature

When you sign Part II, you’re making four statements under penalty of perjury:

The TIN you gave is correct.
You are not currently subject to backup withholding, or you are and have crossed out that statement as the form instructs.
You’re a U.S. citizen, U.S. resident alien, or other U.S. person.
Any FATCA codes you entered are correct.

Sign and date the form. Without a signature, the requester cannot treat it as valid and may be required to withhold 24 percent of every payment they send you and forward that money to the IRS as backup withholding.⁵

Electronic signatures are accepted when the requester provides a compliant system.²

Delivering the Completed Form

Give the form directly to the person or business that requested it. Do not mail it to the IRS. The IRS doesn’t process W-9s.¹

Because the form carries your Social Security Number or EIN, treat it like any sensitive financial document. If you’re sending it electronically, use encrypted email or a password-protected file rather than an unsecured attachment. Hand delivery and postal mail are fine alternatives. Keep a copy so you can check what you submitted if a 1099 arrives with wrong information.

When to Send an Updated W-9

A completed W-9 has no set expiration, but you need to send a new one whenever the information on the original changes. Common triggers:

A legal name change.
A new TIN or EIN.
A change in business structure, such as converting a sole proprietorship into an LLC taxed as an S corporation.
A change of address.

You also need to submit a new form if you previously claimed to be an exempt payee but no longer qualify, for instance a C corporation that elects S corporation status, or an organization that loses its tax-exempt status.¹

Foreign Persons Use a Different Form

Form W-9 is only for U.S. persons: U.S. citizens, resident aliens, and domestic entities. A foreign individual or foreign entity receiving payments from a U.S. source uses Form W-8BEN (individuals) or Form W-8BEN-E (entities) instead.⁶

The withholding rules differ significantly. A payer who receives a W-9 reports income on a 1099 with no automatic withholding (as long as backup withholding doesn’t apply). A payer who receives a W-8 form typically withholds 30 percent unless a tax treaty reduces the rate. Submitting the wrong form leads to either excess withholding or incorrect reporting.

What Happens If You Get It Wrong

The Part II certification is signed under penalty of perjury. Deliberately supplying a false TIN or lying about your tax status can be prosecuted as a felony under 26 U.S.C. § 7206, carrying a fine of up to $100,000 (up to $500,000 for a corporation), up to three years’ imprisonment, or both.⁷

Short of that, simply failing to provide your TIN when properly asked triggers 24 percent backup withholding on every reportable payment. The requester must start withholding and remitting until you supply a valid TIN. The IRS can also impose a $50 civil penalty for each failure to furnish a correct TIN, up to $100,000 in a calendar year.⁸

Fixing a mismatch after the IRS flags it means several rounds of notices among you, the payer, and the IRS, and backup withholding keeps running until the problem is resolved.⁵ Fill it out accurately the first time.

1
Internal Revenue Service. Form W-9 (Rev. March 2024)
2
Internal Revenue Service. Instructions for the Requester of Form W-9 (03/2024)
3
Internal Revenue Service. Instructions for the Requester of Form W-9 (Rev. March 2024)
4
Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers
5
Internal Revenue Service. Information Return Penalties
6
Internal Revenue Service. About Form W-8 BEN, Certificate of Foreign Status of Beneficial Owner for United States Tax Withholding and Reporting (Individuals)
7
Office of the Law Revision Counsel. 26 USC 7206 – Fraud and False Statements
8
Office of the Law Revision Counsel. 26 USC 6723 – Failure To Comply With Other Information Reporting Requirements