The business structure question is one that most attorneys either overcomplicate or under-research. The answer depends on three things: your state's rules on what entities attorneys can form, your tax situation, and how the firm is structured for liability purposes.

This guide covers the four main options, what each one means practically, and how to pick the right one for your situation.

The Four Main Options for Law Firms

Sole Proprietorship

The default structure for attorneys who have not formed a separate entity. You are the business. All income is your personal income. All liability is personal liability. There is no legal separation between you and the firm.

The only reason to operate as a sole proprietor: you are testing the waters before committing to a formal entity. For any attorney planning to practice longer than 6 months, the lack of liability protection makes this an unacceptable long-term structure.

Professional Corporation (PC) or Professional Service Corporation (PSC)

Most states require attorneys who form a corporation to use a special entity type: the Professional Corporation (PC) or Professional Service Corporation (PSC). Unlike a standard LLC or corporation, a PC restricts ownership to licensed professionals in the relevant field — meaning only attorneys can own shares in a PC formed by attorneys.

Advantages of a PC: recognized in all 50 states for attorney use, provides corporate liability protection (with some limits in professional liability context), allows retirement account contributions as a corporate employer, and in some states enables favorable S-corp tax treatment.

Disadvantage: more rigid governance requirements than an LLC (board meetings, corporate minutes, annual filings), and higher administrative overhead for maintaining corporate formalities.

Professional Limited Liability Company (PLLC)

In states that permit it — which is most of them — the PLLC is often the default choice for new law firms. It combines the liability protection of a corporation with the operational flexibility and simpler governance of an LLC. A PLLC restricts membership to licensed professionals (same as a PC) but operates on an operating agreement rather than corporate bylaws.

Tax treatment: by default, a single-member PLLC is taxed as a sole proprietor. A multi-member PLLC defaults to partnership taxation. Both can elect S-corp treatment to reduce self-employment tax once income exceeds roughly $80,000 to $100,000 per year.

The PLLC is the most common structure for solo and small law firms in 2026 because of its flexibility. Check whether your state specifically authorizes PLLCs for attorneys — a small number of states restrict attorney entities to the PC structure only.

Limited Liability Partnership (LLP)

The LLP is the standard structure for traditional multi-partner law firms. It provides each partner with protection from liability for the malpractice or misconduct of other partners (which is the specific concern in a partnership) while maintaining the pass-through taxation of a partnership.

LLPs are appropriate when two or more attorneys with equity stakes are forming a firm. They are not appropriate for solo practitioners — a solo cannot have a general partner and a limited partner simultaneously.

What Business Structure Does Not Protect You From

A common misconception: forming a PC or PLLC fully protects you from malpractice claims. It does not. The professional liability exception to entity protection means that your personal assets remain exposed for your own professional negligence regardless of your business structure. The entity structure protects you from a partner's malpractice (in a partnership context) and from general business liabilities (contracts, employment claims, landlord disputes) — but not from your own professional conduct.

This is why malpractice insurance is required regardless of entity structure. The business structure and the insurance coverage serve different protective functions.

The Tax Dimension

This is where the structure decision gets more nuanced. Work with a CPA — specifically one who works with professional service firms — before finalizing your structure. The general framework:

Sole proprietor or single-member LLC (disregarded entity): All income is subject to self-employment tax (15.3% on the first $168,600 in 2026, 2.9% above that). Simple, but expensive at higher income levels.

S-Corp election (available to PC, PLLC, or standard LLC): You pay yourself a "reasonable" W-2 salary. Profit distributions above the salary are not subject to self-employment tax. On $300,000 net income, paying yourself $150,000 in salary and $150,000 in distributions saves roughly $10,000 to $15,000 in self-employment tax annually. The tradeoff: more administrative complexity (payroll, separate business bank accounts, quarterly filings).

Partnership taxation (LLP, multi-member LLC): Income flows through to each partner's personal return based on the partnership agreement. No entity-level income tax. Each partner pays self-employment tax on their distributive share unless the structure is arranged otherwise.

The Decision Framework

Solo, first year, limited capital: Single-member PLLC or PC (depending on state). Disregarded entity for taxes until income justifies S-corp complexity.

Solo with growing income ($150K+ net profit): Evaluate S-corp election with a CPA. The tax savings typically justify the administrative overhead once income is consistent.

Two-attorney firm with equal equity: PLLC or LLP depending on state. Use an operating agreement that addresses profit splits, dispute resolution, exit provisions, and what happens if one partner is suspended or dies.

Multi-partner firm with complex governance: LLP is the standard for this structure. Get a law firm-specific partnership agreement drafted by an attorney who does not work at your firm.

Mistakes That Are Expensive to Fix Later

Not maintaining corporate formalities. If you form a PC but never hold board meetings, keep no corporate minutes, and commingle personal and business funds, a court can pierce the corporate veil and hold you personally liable for business obligations. Maintain the entity properly or you do not have the protections it provides.

Choosing structure before consulting a CPA. The tax implications of the structure decision are significant — the right structure at $100K net income may be wrong at $400K. Get the tax advice before you file the formation documents.

No operating or partnership agreement. The state default rules for LLCs and partnerships are written for the average business, not a law firm. A customized operating agreement addresses equity splits, decision-making authority, what happens when a partner leaves, and how to handle a suspended attorney. Default rules create expensive ambiguity.

Most law firms focus on the structure question and underinvest in the operational infrastructure that determines whether revenue materializes. The business entity is the legal container. The systems inside that container — intake, follow-up, billing, client communication — are what drive revenue. If you are building those systems and want to see what an automated intake and operations stack looks like for a firm at your stage, book a free audit call.