How to Fill Out Form W-9 for a Multi-Member LLC

To fill out Form W-9 for a multi-member LLC, check the “Limited liability company” box on Line 3a and enter a single letter for your federal tax classification: P for partnership, C for C corporation, or S for S corporation.¹ Use the LLC’s legal name and Employer Identification Number, not any member’s name or Social Security Number. Getting any of those three items wrong can trigger 24% backup withholding on every payment the LLC receives.² The form is one page. The classification question is what trips people up.

Know Your Tax Classification First

Every entry on the W-9 depends on how the IRS classifies your LLC for federal tax purposes. A domestic LLC with two or more members is a partnership by default.³ The entity files Form 1065 and issues each owner a Schedule K-1.⁴ Most multi-member LLCs never change this.

Your LLC has a different classification only if it affirmatively elected one. Form 8832 switches the LLC to corporate treatment.⁵ Form 2553 elects S corporation status.⁶ If you’re not sure what your LLC filed, look at the return the LLC actually submitted last year. A 1065 means partnership. A 1120 means C corporation. A 1120-S means S corporation.

One boundary worth naming: married couples who co-own an LLC cannot use the qualified joint venture election to bypass partnership treatment. The IRS excludes LLCs from that election, which is limited to unincorporated businesses.⁷ A spouse-owned multi-member LLC files as a partnership unless it has elected corporate treatment.

Line 1: Legal Name

Enter the LLC’s legal name exactly as it appears on the entity’s tax return and as it’s registered with the IRS under your EIN.⁸ Small discrepancies matter. “ABC Ventures LLC” and “ABC Ventures, LLC” can produce a mismatch. Pull out the SS-4 confirmation letter or a recent tax return and copy the name character for character.

Line 2: DBA or Trade Name

Line 2 is optional. Fill it in only if the LLC operates under a different name than the one on Line 1. If your registered name and your trade name are the same, leave this blank.

Line 3a: Check the LLC Box and Enter the Right Letter

This line is where multi-member LLCs make most of their mistakes. Line 3a offers checkboxes for Individual/sole proprietor, C Corporation, S Corporation, Partnership, Trust/estate, and Limited liability company. Do not check the standalone Partnership, C Corporation, or S Corporation box, even if that describes how you’re taxed. Check “Limited liability company” and write in the letter for your classification:¹

P if the LLC is classified as a partnership (the default)
C if the LLC elected C corporation treatment
S if the LLC elected S corporation treatment

The standalone Partnership and Corporation boxes are for entities actually formed as partnerships or corporations under state law. An LLC is a different legal structure, even when the IRS taxes it identically to one of those. Checking the wrong box misidentifies your entity type to the payer and creates reporting problems later.

Never check “Individual/sole proprietor or single-member LLC.” A multi-member LLC is not a single-member LLC, and this selection produces a mismatch with IRS records when the payer files information returns.⁹

Line 3b: Foreign Partners

The January 2026 revision of Form W-9 adds Line 3b for partnerships (including LLCs classified as partnerships) that have any foreign partners, owners, or beneficiaries. Check this box if any partner has provided you a Form W-8, or if any partner gave you a W-9 with their own Line 3b checked.¹ If every member is a U.S. person, skip this line.

Line 4: Exemption Codes

Line 4 has two small fields: an exempt payee code and a FATCA reporting code.

A multi-member LLC taxed as a partnership generally is not an exempt payee. Leave the field blank. An LLC taxed as a C corporation or S corporation can enter exempt payee code 5 (“A corporation”), which exempts it from backup withholding on most payment types.⁹

The FATCA code applies only to accounts maintained outside the United States. A typical domestic LLC with U.S. accounts leaves it blank; the payer may pre-populate it with “N/A.”⁹

Lines 5 and 6: Address

Line 5 takes the street address, including any suite or unit number. Line 6 takes the city, state, and ZIP code. Use the LLC’s business address rather than a member’s home address. This is where 1099s and IRS correspondence will be mailed, so use wherever the LLC reliably receives mail.

Part I: Enter the LLC’s EIN

Part I asks for the LLC’s Taxpayer Identification Number. For a multi-member LLC, that means the entity’s Employer Identification Number, no matter which tax classification you selected on Line 3a.¹⁰

Do not enter a member’s Social Security Number or ITIN. A multi-member LLC is a separate entity for tax purposes and must use its own EIN. The TIN on the form must match the name on Line 1, or the payer will be told to start backup withholding.⁸

Using a member’s SSN is probably the single most common W-9 error for multi-member LLCs. It virtually guarantees an IRS mismatch notice back to the payer.

Part II: Sign, Date, and Submit

Part II is the certification. By signing, the authorized person confirms that the TIN is correct, that the LLC is not currently subject to backup withholding (or, if it is, that the payer has been notified), and that the FATCA code, if any, is accurate.¹

The signer must have authority to bind the LLC. That’s typically a managing member or an officer designated in the operating agreement. If the operating agreement is silent on tax forms, any member authorized to act on the LLC’s behalf can sign.

Electronic signatures are accepted if the system verifies the signer’s identity, can reproduce the form on request, and carries the perjury statement from the paper version. Most secure vendor portals meet those requirements. If you’re emailing the completed form, use encrypted email or a secure file-sharing service. The W-9 contains your EIN and other sensitive information.

Do not send the W-9 to the IRS. It stays with the payer, who uses it to prepare information returns. Keep a copy for your own records.

What Happens If Something Is Wrong

The IRS cross-checks the Line 1 name, the Line 3a classification, and the EIN against its own records. When something doesn’t match, the payer hears about it first, and then the LLC does.

B-Notices

If the IRS detects a TIN mismatch on an information return, it sends the payer a CP2100 or CP2100A notice. The payer then sends the LLC a “First B Notice” with a blank W-9, asking for corrected information. A second mismatch within three years brings a “Second B Notice.” At that point a corrected W-9 is not enough; the LLC must provide a copy of IRS Letter 147C verifying the EIN.¹¹

24% Backup Withholding

If the LLC doesn’t respond to a B notice, or if the TIN was missing or obviously wrong to begin with, the payer must withhold 24% of every reportable payment and send it directly to the IRS.² The LLC can claim credit for the withheld amount on its tax return, but the cash is gone in the meantime. Filling in the W-9 correctly on the first try avoids the whole problem.

How Your Classification Affects Whether You’ll Receive a 1099

The letter you enter on Line 3a has a practical downstream effect. If your LLC is classified as a partnership, the payer must report payments to it on Form 1099-NEC or 1099-MISC, the same as for any non-corporate payee. For tax years beginning in 2026, the reporting threshold for most of these payments rises from $600 to $2,000.¹²

If your LLC elected C or S corporation treatment, most payments are exempt from 1099 reporting. The payer sees the C or S code and knows a 1099 generally isn’t required. Exceptions still apply: payments for legal services, medical and health care payments, and gross proceeds paid to attorneys must be reported even to corporations.¹³

None of this changes what the LLC owes. Income is taxable whether or not a 1099 arrives. It only changes how much paperwork the payer sends, and how many matching notices you’re likely to see.

1
Internal Revenue Service. Form W-9 (Rev. January 2026)
2
Internal Revenue Service. Backup Withholding
3
eCFR. 26 CFR 301.7701-3 – Classification of Certain Business Entities
4
Internal Revenue Service. About Form 1065, U.S. Return of Partnership Income
5
Internal Revenue Service. About Form 8832, Entity Classification Election
6
Internal Revenue Service. Instructions for Form 2553
7
Internal Revenue Service. Election for Married Couples Unincorporated Businesses
8
Internal Revenue Service. Form W-9 (Rev. March 2024)
9
Internal Revenue Service. Instructions for the Requester of Form W-9 (Rev. March 2024)
10
Internal Revenue Service. Employer Identification Number
11
Internal Revenue Service. Backup Withholding “B” Program
12
Internal Revenue Service. 2026 Publication 1099
13
Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC