How does an LLC complete IRS Form W-9?A Limited Liability Company (LLC) is a legal entity organized under state law, not a federal tax classification. Under Treasury Regulation § 301.7701-3 (“check-the-box” regulations), the IRS classifies every LLC into one of four distinct tax structures: Disregarded Entity, Partnership, S-Corporation, or C-Corporation.
The most frequent compliance error occurs with Single-Member LLCs (disregarded entities): you must enter the individual owner's legal name on Line 1, check the “Individual/sole proprietor or single-member LLC” box on Line 3a (never the LLC box), and provide the owner's SSN or EIN in Part I. Multi-member LLCs write the company name on Line 1, check the LLC box on Line 3a with classification letter “P” (Partnership), and use the business EIN. Corporate-elected LLCs enter letter “S” or “C” and claim Exemption Code 5 on Line 4.
Key Takeaways for 2026 Compliance
- Single-Member LLCs (disregarded entities) MUST enter the individual owner's legal name on Line 1 — not the LLC name.
- On Line 3a, Single-Member LLCs check "Individual/sole proprietor or single-member LLC" — DO NOT check the LLC box.
- Multi-Member LLCs check "Limited liability company" on Line 3a and enter the capital letter "P" for Partnership.
- Corporate-elected LLCs write "S" (S-Corporation) or "C" (C-Corporation) on Line 3a and claim Exemption Code 5 on Line 4.
- Putting the LLC entity name on Line 1 of a Single-Member LLC triggers an IRS CP2100 B-Notice and 24% backup withholding.
- For 2026, clients must issue Form 1099-NEC to unincorporated LLCs for payments of $2,000+ ($600 prior to 2026 under OBBBA).
- Foreign-owned SMLLCs cannot use W-9; the foreign owner provides Form W-8BEN/W-8BEN-E and faces a $25,000 Form 5472 penalty for non-filing.
- Line 3b (Rev. March 2024) is mandatory for partnership LLCs with foreign partners providing a W-9 to flow-through entities.
More than 80% of newly formed small businesses in the United States choose the Limited Liability Company (LLC) structure because of its state-level liability protection and operational flexibility. However, when an accounts payable team or client requests an IRS Form W-9, LLC owners frequently encounter severe confusion: Do I write my personal name or my business name? Which box do I check on Line 3? Should I provide my Social Security Number or my business Employer Identification Number (EIN)?
The underlying source of this confusion is statutory: the Internal Revenue Code does not recognize an “LLC” as a federal tax classification. Under Treasury Regulation § 301.7701-3 (the federal “check-the-box” regulations), an LLC is legally classified as either a disregarded entity, a partnership, or an association taxable as a corporation (S-Corp or C-Corp).
Making an error on Form W-9 is not merely a cosmetic blemish. If a single-member LLC puts its business name on Line 1 with the owner's SSN, the IRS automated TIN matching system returns an error. This triggers an IRS CP2100 “B-Notice” to your client, legally compelling them to withhold 24% backup withholding under 26 U.S. Code § 3406 from every future invoice.
This guide provides an authoritative, CPA-reviewed roadmap to completing Form W-9 for every LLC classification, updated for the Rev. March 2024 form revision and the 2026 tax year. If you need to generate a verified, rejection-proof PDF immediately, you can use our Free W-9 Online Generator or cross-reference general filing rules in our Step-by-Step Form W-9 Guide.
1. The 4 LLC Tax Classifications & “Check-the-Box” Rules
Core Tax Rule: An LLC does not have its own federal tax category. By default, a single-owner LLC is taxed as a disregarded entity (sole proprietorship), while a multi-owner LLC is taxed as a partnership. Either structure can formally elect corporate tax treatment by filing IRS Form 8832 (C-Corporation) or Form 2553 (S-Corporation). How you complete Lines 1, 2, 3a, 4, and Part I of Form W-9 depends strictly on this tax classification.
To complete Form W-9 correctly, you must first identify which of the four federal tax classifications applies to your LLC:
Single-Member LLC (Disregarded)
The LLC is ignored for federal income tax purposes. All income and expenses flow directly to the individual owner's Form 1040 (Schedule C, E, or F).
Multi-Member LLC (Partnership)
The LLC files an annual partnership information return on Form 1065 and issues Schedule K-1s to members.
S-Corporation LLC (Subchapter S)
The LLC filed IRS Form 2553 to be taxed as a pass-through corporation, filing Form 1120-S and paying W-2 wages to owner-employees.
C-Corporation LLC (Subchapter C)
The LLC filed IRS Form 8832 electing to be taxed as a standard corporation, filing Form 1120 and paying corporate income tax directly.
2. Avoiding the #1 IRS Error: Single-Member Name/TIN Mismatch
According to IRS data, more than 70% of all information return mismatch penalties stem from single-member LLCs misidentifying their legal name on Line 1. This error occurs because business owners intuitively assume that having an LLC name and an EIN means the LLC is an independent taxpayer in IRS master files.
The Fatal Single-Member Trap: CP2100 B-Notice & 24% Withholding
When your client files Form 1099-NEC at year-end, the IRS automated validation system checks Line 1 against Social Security Administration (SSA) and IRS records. A single-member LLC does not file a corporate return. If you put the LLC name on Line 1 alongside your SSN, the IRS computer matches your SSN against your company name—resulting in an immediate TIN Mismatch (Match Code 2).
To learn how clients must legally respond when a B-Notice is received, review our dedicated breakdown on IRS backup withholding rules and contractor refusal penalties.
3. Master Form W-9 Field-by-Field Reference Matrix for LLCs
Use this comprehensive reference matrix to determine exactly what to enter on each line of the revised Form W-9 across all four federal tax classifications:
| LLC Tax Status | Line 1 (Legal Name) | Line 3a Checkbox | Line 4 Code | Part I TIN | 1099-NEC? |
|---|---|---|---|---|---|
| Single-Member LLC Disregarded Entity | Individual Owner Name | Individual / Sole Proprietor | Leave blank | Owner SSN (or EIN) | YES ($2,000+ in '26) |
| Multi-Member LLC Default Partnership | Legal LLC Name | LLC → Code “P” (Check 3b if foreign partners) | Leave blank | Partnership EIN | YES ($2,000+ in '26) |
| S-Corporation LLC Form 2553 Election | Legal LLC Name | LLC → Code “S” | Code 5 | Corporate EIN | EXEMPT* |
| C-Corporation LLC Form 8832 Election | Legal LLC Name | LLC → Code “C” | Code 5 | Corporate EIN | EXEMPT* |
*Statutory Corporate Exceptions: S-Corps and C-Corps remain subject to mandatory 1099 reporting for attorney legal fees (1099-NEC Box 1 / 1099-MISC Box 10 under IRC § 6045(f)) and medical/healthcare service payments (1099-MISC Box 6 under IRC § 6041).
4. Are LLCs Exempt From Form 1099-NEC Reporting? (2026 Thresholds)
Direct Compliance Rule: No, forming an LLC does not automatically exempt you from receiving a Form 1099-NEC. Under Treasury Regulation § 1.6041-3(p)(1), corporate payees are generally exempt from information reporting, but unincorporated entities—including Single-Member LLCs and Multi-Member Partnerships—are fully subject to 1099-NEC reporting.
When an accounts payable department pays an LLC for services, the tax treatment depends on the entity's check-the-box status and the annual aggregate dollar amount:
SMLLCs & Partnerships Must Receive 1099-NEC
Under the One Big Beautiful Bill Act (OBBBA, Pub. L. 119-21), effective for tax year 2026, clients must issue Form 1099-NEC if cumulative service payments reach $2,000 or more ($600 for tax years prior to 2026). For a comprehensive historical breakdown of this statutory change, see our guide to the 2026 $2,000 threshold vs historical $600 rule.
S-Corps & C-Corps Are Generally Exempt (Line 4 Code 5)
Once an LLC files Form 2553 (S-Corp) or Form 8832 (C-Corp), it qualifies as an exempt corporate payee under Treas. Reg. § 1.6041-3(p)(1). Clients do not issue 1099-NEC for standard consulting, design, or vendor services.
The Two Mandatory Exceptions to Corporate Exemption: Even if your LLC is taxed as an S-Corporation or C-Corporation, clients MUST still issue an information return in two specific statutory scenarios:
- Attorney Legal Fees (26 U.S.C. § 6045(f)): All payments made to an attorney or law firm for legal services must be reported on Form 1099-NEC (Box 1) or Form 1099-MISC (Box 10 for gross proceeds), regardless of whether the legal practice is an LLC, S-Corp, or professional corporation.
- Medical and Health Care Payments (26 U.S.C. § 6041): Payments made in the course of business to corporate healthcare providers, clinics, or physicians must be reported on Form 1099-MISC (Box 6).
5. Special Ownership Scenarios: Spousal, Parent-Subsidiary & Series LLCs
Not all LLCs conform to standard individual or independent partnership models. Review the specific statutory rules governing specialized LLC ownership arrangements:
Husband-and-Wife LLCs (Rev. Proc. 2002-69)
In the nine community property states (AZ, CA, ID, LA, NV, NM, TX, WA, WI), an LLC owned solely by a married couple as community property can elect under Revenue Procedure 2002-69 to be treated as either a Partnership or a Disregarded Entity (Qualified Joint Venture). If electing disregarded status, one spouse enters their name on Line 1, checks Individual/sole proprietor on Line 3a, and avoids filing Form 1065. In the other 41 common-law states, a husband-and-wife LLC is strictly classified as a partnership.
Parent-Subsidiary & Holding Entity LLCs
If your Single-Member LLC is 100% owned by another entity (such as a parent corporation, partnership, or holding LLC), IRS instructions state that Line 1 must contain the legal name of the parent entity. The subsidiary LLC name is entered on Line 2. On Line 3a, check the box corresponding to the parent entity's tax classification, and enter the parent entity's EIN in Part I. Never enter the disregarded subsidiary LLC's name on Line 1.
Series LLC Cells & Protected Cells
Under Proposed Treasury Regulation § 301.7701-1, each individual series cell established under state law (e.g., Delaware, Texas, or Wyoming Series LLCs) is treated as a separate federal taxpayer entity if it holds separate assets and maintains independent books. Each cell must obtain its own EIN and issue its own Form W-9 reflecting its individual tax classification.
6. Foreign-Owned LLC Compliance: W-9 vs. W-8BEN & Form 5472 Mandates
Critical International Rule: Under IRS instructions, a U.S. Single-Member LLC owned by a non-resident alien or foreign corporation cannot provide Form W-9 to clients for U.S.-source income if it is treated as a default disregarded entity. Because the entity is disregarded, the payee is deemed to be the foreign owner. The foreign owner must document their status using Form W-8BEN (for individuals) or Form W-8BEN-E (for entities).
The table below establishes the authoritative decision framework for foreign-owned LLCs operating in the United States:
| Entity Scenario | IRS Form Required | Default Withholding | Statutory Obligation |
|---|---|---|---|
| Foreign-Owned Disregarded SMLLC Sole owner is non-U.S. person | Form W-8BEN (Individual) or Form W-8BEN-E (Entity) | 30% default (reducible via bilateral tax treaty) | Form 5472 + Pro-Forma Form 1120 ($25,000 penalty) |
| Foreign-Owned LLC Elected C-Corp Filed IRS Form 8832 | Form W-9 (Domestic Corporation) | 0% (Exempt Payee - Code 5) | Standard corporate Form 1120 return |
| Multi-Member LLC with Foreign Partner Partnership classification | Form W-9 (Checks Line 3a “P” + Line 3b) | 0% from payer; LLC withholds under IRC § 1446 | Forms 1065, 8804, 8805 & Schedule K-1 |
Statutory Warning: Form 5472 Mandatory Filing ($25,000 Penalty)
Under 26 U.S. Code § 6038A and Treasury Regulation § 1.6038A-2, every U.S. disregarded Single-Member LLC that has 25% or greater foreign ownership is legally treated as an association taxable as a corporation solely for international tax reporting.
For an exhaustive side-by-side analysis of bilateral tax treaties, Foreign Tax Identification Numbers (FTINs), and platform rules (Stripe, Upwork, PayPal), read our dedicated pillar on W-9 vs. W-8BEN for International Contractors & Businesses.
7. Step-by-Step Form W-9 Line Instructions for LLCs (Rev. March 2024)
Follow this field-by-field protocol to complete every line of the current IRS Form W-9 (Rev. March 2024):
Enter the legal name of the person or entity whose federal income tax return includes the income reported on this form. For a Single-Member LLC, enter the individual owner's personal legal name (as reported on Form 1040). For Multi-Member LLCs, S-Corps, and C-Corps, enter the registered legal entity name exactly as approved by your Secretary of State and confirmed on IRS CP 575 notice.
If you operate a Single-Member LLC, write the registered business name of the LLC on Line 2. If your multi-member or corporate LLC conducts business under a Doing Business As (DBA) or fictitious trade name, enter that trade name here. If you have no trade name, leave Line 2 completely blank.
Line 3a: Check only ONE box. A Single-Member LLC must check “Individual/sole proprietor or single-member LLC”. All other LLCs check “Limited liability company” and enter the appropriate classification letter: P (Partnership), S (S-Corporation), or C (C-Corporation). Leaving this letter blank invalidates the document.
Line 3b (Mandatory for Flow-Through Entities): Added in the March 2024 revision. If you checked “LLC” with classification letter P (or Partnership), and you are submitting this W-9 to a partnership, trust, or estate in which you hold an equity interest, you must check Box 3b if you have direct or indirect foreign partners, owners, or beneficiaries under IRC § 1446.
Single-member LLCs and Partnership LLCs must leave this field blank. LLCs taxed as S-Corporations or C-Corporations may enter Exemption Code 5, certifying that they are exempt payees for Form 1099-NEC nonemployee compensation reporting purposes.
Enter the primary mailing address where your client should mail tax notices and Form 1099 statements. If you move during the year, notify your payers promptly to prevent returned mail.
Enter the 9-digit number that corresponds precisely to the legal entity or person entered on Line 1. For single-member LLCs, enter the owner's SSN (recommended by IRS) or the LLC's business EIN if registered under the owner's SSN. For multi-member partnerships and corporate LLCs, enter the business EIN.
Sign and date the document. By signing Part II, you legally certify under penalties of perjury that: (1) the TIN provided is correct, (2) you are not subject to backup withholding, (3) you are a U.S. citizen or other U.S. person, and (4) any FATCA codes entered are correct.
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Frequently Asked Questions
How does a Single-Member LLC fill out Line 1 and Line 3 on Form W-9?
Under IRS instructions, a Single-Member LLC treated as a disregarded entity must enter the INDIVIDUAL OWNER'S personal legal name on Line 1. The registered name of the LLC goes on Line 2 (Business name / disregarded entity name). On Line 3, check the first box: "Individual/sole proprietor or single-member LLC". Do NOT check the "Limited liability company" box.
Can a Single-Member LLC use its EIN instead of the owner's personal SSN?
The IRS recommends entering the owner's Social Security Number (SSN) in Part I because a disregarded entity does not file a federal income tax return in its own name (its income flows to the owner's Form 1040 Schedule C). However, the IRS also accepts the LLC's Employer Identification Number (EIN), provided that EIN is officially linked to the sole owner's SSN in IRS records.
How does a Multi-Member LLC fill out Line 3 on Form W-9?
A Multi-Member LLC taxed as a default partnership must enter the legal LLC business name on Line 1, leave Line 2 blank (unless operating under an active DBA), check the "Limited liability company" box on Line 3a, and write the capital letter "P" in the tax classification space. If the LLC has foreign partners, it may also need to check Line 3b.
How does an LLC taxed as an S-Corporation fill out Form W-9?
An LLC that filed IRS Form 2553 to be taxed under Subchapter S writes the legal LLC name on Line 1, checks "Limited liability company" on Line 3a, and writes the capital letter "S" in the classification space. On Line 4, enter Exemption Code 5 (exempt payee from Form 1099-NEC nonemployee compensation reporting).
Is an LLC exempt from receiving Form 1099-NEC at year-end?
It depends entirely on the LLC's federal tax classification. Single-Member LLCs (disregarded entities) and Multi-Member LLCs (partnerships) are NOT exempt and must receive Form 1099-NEC for annual payments of $2,000 or more in 2026 ($600 for tax years prior to 2026 under OBBBA). LLCs that elected S-Corporation (S) or C-Corporation (C) status are generally exempt from 1099-NEC reporting, EXCEPT for payments made for attorney legal services (IRC § 6045(f)). Corporate healthcare payments are reportable on Form 1099-MISC Box 6 under IRC § 6041.
What happens if I put my LLC name on Line 1 of a Single-Member LLC?
If you enter your single-member LLC name on Line 1 with your SSN in Part I, the IRS automated TIN matching system will fail because the LLC name is not associated with your personal SSN in the Social Security Administration or IRS master file. This mismatch triggers an IRS CP2100 or CP2100A "B-Notice" to your client, requiring them to immediately implement 24% backup withholding on all future payments.
How does a husband-and-wife LLC fill out Form W-9 in community property states?
In the nine community property states (AZ, CA, ID, LA, NV, NM, TX, WA, WI), an LLC owned solely by a married couple as community property can elect to be treated as a Qualified Joint Venture (disregarded entity) under Rev. Proc. 2002-69, following Single-Member LLC rules. In non-community property states, a husband-and-wife LLC is legally classified as a partnership, requiring Line 3 code "P" and an EIN.
What should a foreign-owned Single-Member LLC do on Form W-9?
Under IRS instructions, if the sole owner of a U.S. Single-Member LLC is a foreign person (non-resident alien or foreign entity) and the LLC is a disregarded entity, the foreign owner cannot certify U.S. person status and must NOT submit Form W-9. Instead, the foreign owner must provide Form W-8BEN (for individuals) or Form W-8BEN-E (for entities) to U.S. clients to document foreign status and claim applicable tax treaty rates.
What is Form 5472 and does my foreign-owned LLC need to file it?
Form 5472 (Information Return of a 25% Foreign-Owned U.S. Corporation or Foreign Corporation Engaged in a U.S. Trade or Business) is mandatory for any U.S. LLC that has 25% or greater foreign ownership. Foreign-owned Single-Member LLCs MUST file Form 5472 with a pro-forma Form 1120 annually, even if the business generated $0 in revenue. The statutory penalty for failing to file is $25,000 per year under IRC § 6038A.
What does Line 3b on the March 2024 Form W-9 mean for LLCs?
Line 3b was introduced in the March 2024 Form W-9 revision. It must be checked if the LLC is classified as a partnership (Line 3a code "P") and is submitting the W-9 to a partnership, trust, or estate in which it holds an ownership interest, and has direct or indirect foreign partners. This ensures compliance with IRC § 1446 foreign partner withholding rules.
Who has legal authority to sign Form W-9 for an LLC?
For a member-managed LLC, any equity member has legal statutory authority to sign Part II under penalties of perjury. For a manager-managed LLC, only the appointed Manager designated in the Operating Agreement may sign. For corporate-elected LLCs, an authorized corporate officer (such as President, CEO, or CFO) must sign under Treas. Reg. § 1.6062-1.
Can I e-sign a Form W-9 for an LLC?
Yes. Under the federal Electronic Signatures in Global and National Commerce Act (E-SIGN Act, 15 U.S.C. § 7001) and IRS Announcement 98-27, electronically signed Form W-9 PDFs with audit-trail verification are 100% legally binding for all LLC entity structures.
- Internal Revenue Service (IRS.gov): IRS Form W-9 (Rev. March 2024) — Request for Taxpayer Identification Number and Certification (OMB No. 1545-0029 / Cat. No. 10231X).Official Source ↗
- Code of Federal Regulations (eCFR): 26 CFR § 301.7701-3 — Classification of Certain Business Entities (Check-the-Box Regulations) (Treas. Reg. § 301.7701-3).Official Source ↗
- Internal Revenue Service (IRS.gov): Single Member Limited Liability Companies — Disregarded Entity Tax Treatment (IRS Small Business & Self-Employed Division).Official Source ↗
- United States Code (Cornell LII): 26 U.S. Code § 6038A — Information with Respect to Certain Foreign-Owned Corporations (Form 5472) (26 U.S.C. § 6038A).Official Source ↗
- Internal Revenue Service (IRS.gov): Revenue Procedure 2002-69 — Tax Treatment of Spousal LLCs in Community Property States (Rev. Proc. 2002-69, 2002-2 C.B. 831).Official Source ↗
- United States Code (Cornell LII): 26 U.S. Code § 3406 — Backup Withholding on Reportable Payments (Mandatory 24% Rate) (26 U.S.C. § 3406).Official Source ↗
- United States Code (Cornell LII): 26 U.S. Code § 6041 & § 6045(f) — Information at Source & Payments to Attorneys (26 U.S.C. §§ 6041, 6045(f)).Official Source ↗