To fill out a W-9 form, download the current March 2024 revision from the IRS website, enter your legal name and tax classification exactly as they appear on your federal tax return, provide your address and Taxpayer Identification Number, sign the certification, and return the completed form to whoever requested it. The W-9 is never filed with the IRS. Most people finish it in about five minutes.
When Someone Will Ask You for a W-9
A payer requests a W-9 whenever they need your TIN to report payments to you on an information return like a 1099. That usually happens when you start work as an independent contractor or freelancer, open a bank or brokerage account, receive certain real estate proceeds, or sign up as a vendor with a business. Signing the form also certifies that you are a U.S. person, which keeps the payer from applying the higher withholding rates that apply to foreign payees under sections 1441 through 1443 of the Internal Revenue Code.1Internal Revenue Service. Instructions for the Requester of Form W-9 (03/2024)
If you are not a U.S. citizen or resident alien, do not use Form W-9. Foreign individuals provide Form W-8BEN instead, and foreign entities use other forms in the W-8 family.2Internal Revenue Service. Instructions for Form W-8BEN If you have a Social Security Number or Employer Identification Number, you are almost certainly the W-9 case.
Filling In Each Line
The form has six numbered lines, an exemptions field, a TIN block, and a signed certification. Take them in order.
Line 1: Your Name
Line 1 asks for the name that matches your federal tax return. For individuals, that is your legal name. For a sole proprietorship or a single-member LLC that the IRS treats as a disregarded entity, put the owner’s personal name on line 1, not the business name. Corporations, partnerships, and trusts enter the entity’s registered name.3Internal Revenue Service. Form W-9 (Rev. March 2024)
This is the field to get right. The IRS matches your name and TIN together when the payer files information returns, and a mismatch can trigger backup withholding at 24% on future payments.4Internal Revenue Service. Backup Withholding
Line 2: Business or Trade Name
Line 2 is for a business name, trade name, or “doing business as” name that differs from what you entered on line 1. Leave it blank if you don’t have one.
Line 3a: Federal Tax Classification
Check one box that describes how your entity is taxed:
- Individual/sole proprietor, if you are a person receiving payment for services or run a sole proprietorship with no separate entity.
- C corporation or S corporation, matching your corporate election.
- Partnership.
- Trust or estate.
- LLC, in which case you also write “C,” “S,” or “P” in the space next to the box to show how the LLC is taxed.3Internal Revenue Service. Form W-9 (Rev. March 2024)
One case trips people up. If you have a single-member LLC that never elected corporate or partnership taxation, the IRS treats it as a disregarded entity and looks through to you. Do not check the LLC box. Check the box that matches the owner’s classification, which for most people is Individual/sole proprietor.
Line 3b: Foreign Partners or Owners
This line was added in the March 2024 revision. Check it only if you selected Partnership, Trust/estate, or LLC taxed as a partnership on line 3a, you are giving this W-9 to another flow-through entity in which you hold an ownership interest, and your entity has any direct or indirect foreign partners, owners, or beneficiaries. Most individuals skip it.3Internal Revenue Service. Form W-9 (Rev. March 2024)
Line 4: Exemption Codes
Line 4 has two small fields for an exempt payee code and a FATCA reporting exemption code. Individuals almost never enter anything here. The codes apply to tax-exempt organizations, government agencies, corporations, registered securities dealers, banks, and certain trusts.5Internal Revenue Service. Instructions for the Requester of Form W-9 (Rev. March 2024) If neither applies, leave both blank.
Lines 5 and 6: Address
Line 5 takes your street address. Line 6 takes your city, state, and ZIP code. Use the address where you want the payer to send information returns and correspondence. If that differs from your legal residence, use the mailing address.
Part I: Taxpayer Identification Number
Under the address lines, Part I asks for your TIN. Individuals use their Social Security Number. Entities use their Employer Identification Number. Resident aliens who cannot get an SSN use an Individual Taxpayer Identification Number.6Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers The form gives you an SSN box and an EIN box side by side. Fill in the one that applies.
Check every digit twice. An incorrect TIN is the single most common reason payers end up withholding 24% of payments and sending it to the IRS.7Internal Revenue Service. Topic No. 307, Backup Withholding
What You’re Signing in Part II
Part II is the certification block. Signing and dating it means you are stating, under penalties of perjury, that:
- The TIN you provided is correct, or you are waiting for one to be issued.
- You are not subject to backup withholding, meaning the IRS has not notified you that you are underreporting interest or dividends, or has since told you withholding no longer applies.
- You are a U.S. citizen or other U.S. person.
- Any FATCA exemption code you entered is correct.3Internal Revenue Service. Form W-9 (Rev. March 2024)
If the IRS has already told you that you are subject to backup withholding for underreporting, cross out item 2 before you sign. The requester should flag this, but the responsibility to strike the language is yours.
Returning the Form Without Exposing Your TIN
You send the completed W-9 back to the person or business that asked for it, not to the IRS. The method depends on what the requester accepts. Most businesses now use a secure online portal or encrypted upload. Some accept fax or physical mail to their accounting or vendor department.
Because the form contains your SSN or EIN, do not send it by unencrypted email. If email is the only option the requester offers, attach a password-protected PDF and share the password by a separate channel. The FTC’s Safeguards Rule requires financial institutions handling customer information to maintain written security programs with administrative, technical, and physical protections.8Federal Trade Commission. FTC Safeguards Rule: What Your Business Needs to Know That duty falls on the requester, but you can still protect yourself on the way there.
Electronic submission is allowed, including by fax, as long as the requester’s system meets IRS conditions: it must confirm that information received matches what was sent, make it reasonably certain the submitter is the person named on the form, present the same content as the paper version, and produce a hard copy on request. The final step must be an electronic signature under penalties of perjury using the same certification language as the paper form.1Internal Revenue Service. Instructions for the Requester of Form W-9 (03/2024)
If Something Is Wrong: Backup Withholding and B-Notices
Once the requester has your W-9, they usually run your name and TIN through the IRS’s free TIN Matching program before filing information returns.9Internal Revenue Service. Taxpayer Identification Number (TIN) Matching A clean match means payments flow without withholding.
If the IRS later flags a mismatch, it sends the payer a CP2100 or CP2100A notice. The payer then sends you a “B-Notice” asking for a corrected TIN. If you don’t respond, the payer must begin backup withholding at 24% no later than 30 business days after receiving the IRS notice. Once you supply a corrected TIN, withholding stops within 30 calendar days.10Internal Revenue Service. Understanding Your CP2100 or CP2100A Notice The fastest fix is a new, corrected W-9 sent immediately.
Backup withholding also kicks in if you refuse to provide a TIN, provide one that is incorrect, or fail to certify that you are not subject to withholding after IRS notification of underreporting.4Internal Revenue Service. Backup Withholding The 24% withheld is not lost. It shows up as a credit on your tax return, the same way regular withholding does. But 24% held back from each payment is a cash-flow problem that a correctly completed form avoids.
When You Need to Send a New W-9
A completed W-9 does not expire. You provide a new one when something on it changes: a legal name change, a new business name, a different TIN (for example, after incorporating and getting an EIN), a change in federal tax classification, or a new mailing address. Some businesses request updated W-9s from vendors at the start of each year even when nothing has changed, to keep their files current.
Answer these requests quickly. When the information on file doesn’t match what you report at tax time, the 1099 amounts and your return diverge, and you end up sorting it out later instead of now.