How to Fill Out a W-9 as an LLC or Sole Proprietor
Last updated September 24, 2026 · Written by the EIN Registration filing team
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| If you are | Line 1 | Line 2 | Line 3a box | Part I number |
|---|---|---|---|---|
| Sole proprietor | Your own name, as on your Form 1040 | Your business or DBA name, if any | Individual/sole proprietor | Your SSN, or your EIN if you have one |
| Single-member LLC, default tax treatment | The owner's name, never the LLC's | The LLC's name | The owner's classification: Individual/sole proprietor for a person | The owner's SSN, or the owner's EIN if the owner has one |
| LLC with two or more members | The LLC's name, as on its tax return | Any DBA name | Limited liability company, with P written in | The LLC's EIN |
| LLC that elected S or C corporation taxation | The LLC's name, as on its tax return | Any DBA name | Limited liability company, with S or C written in | The LLC's EIN |
The single-member LLC is the one people get wrong
By default the IRS treats a single-member LLC as part of its owner. Its income goes on the owner’s own return, so the W-9 is filled in as if the owner were the payee. The form’s instructions say the name on line 1 should never be the disregarded LLC; it is the owner, with the LLC’s name on line 2. The box on line 3a is the owner’s classification, which for a person is “Individual/sole proprietor”, not “Limited liability company”.
The number follows the name: the owner’s SSN, or an EIN the owner holds. That surprises owners who got an EIN for the LLC’s bank account and assumed it goes everywhere. The requester matches the number to the name on line 1, so a number that belongs to a different name produces the mismatch notices the form is designed to avoid.
Everything changes if the LLC elects to be taxed as an S or C corporation, or gains a second member. It is then its own taxpayer: its own name on line 1, the Limited liability company box with S, C or P written in, and its own EIN, which it is required to have. When an LLC is required to have an EIN.
Using an EIN instead of your Social Security number
A sole proprietor who has an EIN may enter it instead of their SSN. That is the main practical reason freelancers and contractors get one: a W-9 goes to every client, and each copy sits in someone else’s files. With an EIN on the form, the SSN stays off all of them. Why most sole proprietors get an EIN anyway.
If you do not have the number yet
The form allows for this. Apply for the number, write “Applied For” in the space for the TIN, sign and date the form, and give it to the requester. Then send the number as soon as it arrives. A payer who does not receive a TIN has to start backup withholding, which the form puts at 24% of the payments, and that money only comes back when you file your return.
Lines 3b and 4, which most small businesses leave blank
Line 3b is for partnerships, trusts and estates that have foreign partners, owners or beneficiaries, and only when the form is going to a partnership, trust or estate they have an interest in. Line 4 holds exemption codes for specific payees, mainly corporations, tax-exempt organizations and financial institutions. A sole proprietor or a single-member LLC normally leaves both blank.
Quick answers
Should my single-member LLC put its EIN on a W-9?
Not under the form’s own instructions, while the LLC keeps its default tax treatment. The name on line 1 is the owner’s, and the number is the owner’s SSN or the owner’s own EIN.
Do I need an EIN to fill out a W-9?
Only if the business is its own taxpayer: an LLC with two or more members, or one taxed as a corporation. A sole proprietor or a default single-member LLC can use the owner’s SSN.
What is a TIN on a W-9?
TIN means taxpayer identification number, the family name for SSNs, ITINs and EINs. The W-9 asks for whichever one belongs to the name on line 1. What a TIN number is.
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Related guides
- Does an LLC Need an EIN? When It Is Required and When It Is Not Required for multi-member LLCs, LLCs with employees, and S or C elections. A single-member LLC with no employees can use the owner's SSN for federal tax, but the bank, payment processors and W-9s make the EIN the practical answer. EIN vs SSN, form by form.
- EIN for a Sole Proprietor: Why Most Get One, and When It Becomes Mandatory Most sole proprietors get an EIN to keep their SSN off W-9s, to open a business account, and to be ready to hire. It becomes mandatory with the first employee. What the SS-4 asks a sole proprietor.
- What Is a TIN Number? EIN vs TIN vs SSN vs ITIN A TIN is the family; EIN, SSN and ITIN are members of it. Which one a form is really asking for, and when a business uses the owner's SSN instead of its own EIN.
- EIN for an LLC (LLC Tax ID Number): How to Get One Nearly every LLC needs its own EIN for the bank, and multi-member LLCs and S corporation elections make it mandatory. The LLC lines on the SS-4, the timing after state approval, and the mistakes that get applications rejected.
- EIN for a Partnership or Multi-Member LLC Mandatory, because a partnership files Form 1065 and issues K-1s. When to apply, which partner is the responsible party, and how the SS-4 differs from a single-owner application.
Sources
EIN Registration is an independent document preparation and filing service and is not affiliated with the IRS or any government agency. You can also apply for an EIN directly with the IRS at irs.gov at no cost.