What is Single-Member LLC?

How it works

A single-member LLC ("SMLLC") is the simplest form of US business entity: one owner, limited liability, and — by default — no separate federal income tax. The IRS treats it as a disregarded entity by default under the check-the-box regulations: the LLC's activity is reported as if the owner had performed it directly.

A US-person SMLLC owner reports the activity on Schedule C (or E, F, depending on type) of their Form 1040; a non-resident owner reports any US-source income on Form 1040-NR.

State law gives the SMLLC three things federal tax doesn't:

• Limited liability. Members' personal assets are protected from LLC debts and obligations except in narrow circumstances (personal guarantee, fraud, piercing).
• A clean business identity for contracts, banking, and payment processors.
• Operational flexibility — no shareholders, no board, no minutes required (in most states), single owner sets all decisions via operating agreement.

Federal compliance differs by owner residency:

• US-person owner → Schedule C/E/F on Form 1040, no separate entity return.
• Foreign-person owner → Form 5472 with a pro-forma Form 1120, every year, regardless of income.

Tax classification can change

The SMLLC isn't permanently disregarded. It can elect to be taxed as a corporation by filing Form 8832 (and, optionally, Form 2553 for S-corp election if eligible). Once elected, the entity files Form 1120 (or 1120-S) and pays corporate tax — or passes through under S-corp rules.

The election is significant and not easily reversed: revoking a corporate classification election triggers a five-year lockout under the regulations. Plan deliberately.

When single-member is the right choice

• Solo operations. SaaS, services, freelance, e-commerce — where there's no co-founder and no equity to allocate.
• Tax simplicity. US-person owners avoid Form 1065 partnership filings and Schedule K-1 mechanics. Non-resident owners avoid the Schedule K-1 from a multi-member LLC, which often creates ECI complications.
• Asset-protection holding entities. A single-member LLC can hold real estate, IP, or interests in other LLCs — limiting liability exposure to the assets in that entity.

Examples

• US freelancer with a Wyoming SMLLC. Reports $80,000 of net consulting income on Schedule C. Pays self-employment tax on the net (15.3% up to the Social Security wage base, then 2.9% Medicare). No 1065, no K-1, no separate entity return.
• French founder with a Delaware SMLLC selling SaaS to European clients. No US trade or business. Federal income tax owed: $0. Annual filing: Form 5472 + pro-forma 1120 — capital contributions and distributions reported as the only "transactions". Delaware franchise tax: $300/year.

Common mistakes

• Adding a second member without thinking. A spouse or co-founder added mid-year converts the LLC from disregarded to partnership. The IRS now expects Form 1065 + K-1s starting from the conversion date. Banks and payment processors care less, but the federal filing changes meaningfully.
• Forgetting Form 5472. The single most expensive paperwork miss for foreign-owned SMLLCs. $25,000/year penalty per missed form.
• Confusing "disregarded for tax" with "ignored legally". The SMLLC is real for everything except federal income tax — banking, contracts, lawsuits, BOI reporting, EIN, state law all treat it as a separate entity.
• Skipping the operating agreement. Most states don't require one for SMLLCs, but it documents the limited-liability structure and avoids piercing-the-veil arguments. Cheap insurance against future creditor litigation.