Form W-9: when to ask for it and how to fill it in

The W-9 is a short form, but errors on it flow straight into 1099s, IRS mismatch notices and backup withholding. This guide covers when to ask for one, how each line is completed, and the single-member LLC rule people most often get wrong.

By Awais Jameel, Chartered Accountant. Reviewed by Muhammad Bilal, Chartered Accountant. Checked against official sources on . 3 minute read.

Short answer

Form W-9 is how a US person gives their correct name and taxpayer number to a business that must report payments to them, such as on Form 1099-NEC. Ask for it before paying a US contractor. A single-member LLC enters the owner's name and number, not the LLC's EIN. Foreign persons give a Form W-8 instead.

At a glance

Who fills it in
US persons, including individuals, LLCs, partnerships and corporations
Who asks for it
A business or platform that must report payments to the person
Sent to the IRS?
No. The requester keeps it
Single-member LLC
Owner's name on line 1, LLC name on line 2, owner's number in Part I
Missing or wrong number
Payer may have to withhold 24% as backup withholding
Foreign persons
Give Form W-8BEN or W-8BEN-E instead
Form W-9: when to ask for it and how to fill it inWho fills it in: US persons, including individuals, LLCs, partnerships and corporations; Who asks for it: A business or platform that must report payments to the person; Sent to the IRS?: No. The requester keeps it; Single-member LLC: Owner's name on line 1, LLC name on line 2, owner's number in Part I; Missing or wrong number: Payer may have to withhold 24% as backup withholding; Foreign persons: Give Form W-8BEN or W-8BEN-E instead.KEY FACTS AT A GLANCEForm W-9: when to ask for it and how to fill it inWho fills it inUS persons, includingindividuals, LLCs,partnerships andcorporationsWho asks for itA business or platformthat must report paymentsto the personSent to the IRS?No. The requester keepsitSingle-member LLCOwner's name on line 1,LLC name on line 2,owner's number in Part IMissing or wrong numberPayer may have towithhold 24% as backupwithholdingForeign personsGive Form W-8BEN orW-8BEN-E insteadChecked against official sourcesTax BakersForm W-9: when to ask for it and how to fill it inWho fills it in: US persons, including individuals, LLCs, partnerships and corporations; Who asks for it: A business or platform that must report payments to the person; Sent to the IRS?: No. The requester keeps it; Single-member LLC: Owner's name on line 1, LLC name on line 2, owner's number in Part I; Missing or wrong number: Payer may have to withhold 24% as backup withholding; Foreign persons: Give Form W-8BEN or W-8BEN-E instead.KEY FACTS AT A GLANCEForm W-9: when to ask for it andhow to fill it inWho fills it inUS persons, including individuals, LLCs,partnerships and corporationsWho asks for itA business or platform that must reportpayments to the personSent to the IRS?No. The requester keeps itSingle-member LLCOwner's name on line 1, LLC name on line 2,owner's number in Part IMissing or wrong numberPayer may have to withhold 24% as backupwithholdingForeign personsGive Form W-8BEN or W-8BEN-E insteadChecked against official sourcesTax Bakers
Key facts at a glance, as set out in this guide.

What is Form W-9 for?

A business that pays someone in a way the IRS requires to be reported, such as paying a contractor $2,000 or more during 2026, needs that person's legal name and taxpayer identification number to put on the information return. Form W-9 is how the payee provides them, and certifies that the number is correct and that they are a US person. The requester keeps the form. It is not sent to the IRS.

When should a business ask for one?

Before the first payment to any US contractor or vendor you may need to report. Asking in January, when 1099s are due, is too late to be useful, and some contractors will be hard to reach by then. Banks, brokers, platforms and marketplaces also ask for W-9s from their US customers.

How do you fill it in?

LineWhat to enter
Line 1The name that matches your tax return: an individual's name, or the entity's legal name. For a disregarded single-member LLC, the owner's name
Line 2A business name, trade name or the disregarded LLC's name, if different from line 1
Line 3aThe federal tax classification: individual or sole proprietor, C corporation, S corporation, partnership, trust or estate, or LLC with its tax classification
Line 3bFor partnerships, trusts and estates that have foreign partners, owners or beneficiaries, a checkbox added in the 2024 revision
Line 4Exemption codes, which apply to certain payees such as corporations for some reporting. Most individuals leave it blank
Lines 5 and 6Address, which the payer uses to send your 1099
Part ISocial Security number, ITIN or EIN
Part IISignature and date, certifying the number is correct and you are a US person

How does a single-member LLC complete it?

This is where most errors happen. A single-member LLC that is disregarded for tax is ignored by the IRS, so the W-9 is completed in the owner's name. The W-9 instructions tell the owner to enter their own name on line 1, the LLC's name on line 2, and the owner's Social Security number, or the owner's own EIN if they have one, in Part I, not the LLC's EIN. An LLC taxed as a partnership or corporation gives its own name and EIN. See does a single-member LLC need an EIN.

What happens if the number is missing or wrong?

If a payee does not provide a taxpayer number, or the IRS notifies the payer that the name and number do not match, the payer may have to withhold 24% of future payments as backup withholding and pay it to the IRS. The payee can claim it against their own tax. Payers who file 1099s electronically can check name and number combinations in advance through the IRS TIN matching program.

The full process, including IRS B notices, is in backup withholding explained.

What do foreign persons give instead?

A W-9 is only for US persons. A foreign individual gives Form W-8BEN and a foreign entity gives Form W-8BEN-E, which certify foreign status. See how to fill in Form W-8BEN. A single-member US LLC owned by a foreign individual is ignored for income tax, so payers usually ask the owner for a W-8BEN. See W-8BEN vs W-8BEN-E vs W-8ECI. See how to open a US LLC from outside the US.

Is it safe to send a W-9?

It contains a taxpayer number, so send it only to payers you know, and through a secure channel rather than ordinary email where possible. Giving clients an EIN instead of a Social Security number, where you have one, reduces the risk if a form goes astray. See what an EIN is.

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Questions people ask

Does Form W-9 go to the IRS?

No. The business that requested it keeps it and uses the details on information returns such as Form 1099-NEC.

What number does a single-member LLC put on a W-9?

If the LLC is disregarded for tax, the owner's Social Security number, or the owner's own EIN, with the owner's name on line 1. Not the LLC's EIN.

What if a contractor will not give me a W-9?

You may have to apply backup withholding of 24% to payments, and you still need to file the 1099.

Do foreign contractors fill in a W-9?

No. Foreign individuals give Form W-8BEN and foreign entities Form W-8BEN-E.

Sources

Every fee, date and rule on this page was taken from these official and primary sources.

  1. IRS: Form W-9 and instructions (Rev. March 2024)
  2. IRS: Instructions for Forms 1099-MISC and 1099-NEC
  3. IRS: Form W-8BEN
  4. Internal Revenue Code section 3406: backup withholding

Rules and fees change. If you are reading this long after September 30, 2026, confirm the figures with the source before you rely on them.

Payroll and contractorsHow to pay contractors and file their 1099sFederal tax formsForm 1099-NEC: who files and who receives itPayroll and contractorsIndependent contractor or employee: how the IRS tells them apart

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This guide is general information. It is not tax or legal advice for your situation.