W-9 LLC Tax Classification: Which Box Should You Check?
Line 3a of Form W-9 asks for your "Federal tax classification." LLC owners often check the wrong box because "LLC" doesn't clearly map to one answer. Here is the definitive breakdown of which box your LLC should check based on its IRS tax treatment.
The correct W-9 tax classification box for your LLC depends on how it is taxed: Single-member LLC (disregarded entity) → check "Individual/sole proprietor or single-member LLC." Multi-member LLC (partnership) → check "Partnership." LLC with S-corp election → check "S Corporation." LLC with C-corp election → check "C Corporation." Do not check the standalone "Limited Liability Company" box unless specifically applicable to your situation. The correct classification depends on your LLC's current IRS tax treatment.
Understanding Line 3a on Form W-9
Line 3a on Form W-9 presents these checkbox options:
- Individual/sole proprietor or single-member LLC
- C Corporation
- S Corporation
- Partnership
- Trust/estate
- Limited Liability Company (with a field for tax classification letter)
- Other (see instructions)
The "Limited Liability Company" option on Line 3a is not for most LLCs. It is specifically for LLCs that are members of another LLC and have made an entity classification election that doesn't map cleanly to the other boxes. For the vast majority of LLC owners, the correct answer is one of the first five options.
Which Box to Check: LLC-by-LLC Breakdown
| Your LLC Type | IRS Tax Treatment | W-9 Line 3a: Check This Box |
|---|---|---|
| Single-member LLC, no elections made | Disregarded entity (owner's SSN/EIN used) | Individual/sole proprietor or single-member LLC |
| Multi-member LLC, no elections made | Partnership (files Form 1065) | Partnership |
| Any LLC that filed Form 2553 | S-Corporation (files Form 1120-S) | S Corporation |
| Any LLC that filed Form 8832 electing C-corp | C-Corporation (files Form 1120) | C Corporation |
| LLC owned by another LLC with specific election | Varies; see instructions | Limited Liability Company (enter P, S, or C) |
Single-Member LLC: The "Individual" Box
If you own a single-member LLC that is a disregarded entity, check the box labeled "Individual/sole proprietor or single-member LLC."
Even though your business is an LLC, not an individual, the IRS treats a single-member disregarded LLC as the owner for tax purposes. The W-9 form design reflects this — the "Individual" box was specifically extended to include single-member LLCs.
If you've elected S-corp or C-corp treatment for your single-member LLC, check the S Corporation or C Corporation box instead.
Multi-Member LLC: The "Partnership" Box
A multi-member LLC that has not elected corporate taxation is treated as a partnership by the IRS. Check the "Partnership" box on Line 3a.
This applies even if:
- The LLC has only two members
- Members are a mix of individuals and trusts
- The LLC does not use the word "partnership" in its name
The LLC name goes on Line 1, and the LLC's EIN goes in Part I of the W-9.
LLC Taxed as S-Corp: The "S Corporation" Box
If your LLC has filed Form 2553 and received IRS acceptance of the S-corp election, check "S Corporation" on Line 3a. This applies whether the LLC is single-member or multi-member, as long as the S-corp election is in effect.
The LLC's name goes on Line 1 and its EIN in Part I.
LLC Taxed as C-Corp: The "C Corporation" Box
If your LLC has elected C-corp treatment by filing Form 8832 (or by converting to a corporation), check "C Corporation." The LLC's name goes on Line 1 and its EIN in Part I.
The "Limited Liability Company" Box: When to Use It
The "Limited Liability Company" box on Line 3a with the enter-a-letter field is for a narrow scenario: an LLC that is owned by another entity (such as another LLC or corporation) and has made a specific classification election via Form 8832. In this case, you would enter:
- P if the LLC is classified as a partnership
- S if the LLC is classified as an S-corporation
- C if the LLC is classified as a C-corporation
Most individual LLC owners do not use this box. If you are unsure whether this applies to your situation, consult a tax professional.
Your LLC's tax classification depends on what elections have been filed with the IRS since your LLC was formed. If you have never filed Form 2553 or Form 8832, your single-member LLC is a disregarded entity and your multi-member LLC is a partnership by IRS default. When in doubt, consult a CPA or tax attorney.