Choosing a business entity type comes down to three consequences that follow from a single decision: who is personally on the hook for the debts, how the income gets taxed, and how much paperwork you file every year. Most owners land on an LLC, sometimes with an S corporation tax election layered on top. Venture-backed startups use C corporations. Sole proprietorships and general partnerships work only when you have no assets worth protecting and no plans to grow. The rest of this guide walks through what each structure actually does, so you can match the choice to where you’re heading rather than where you are today.
The Three Things That Actually Differ
Every structure sits somewhere on a spectrum. At one end, sole proprietorships and general partnerships require zero paperwork and offer zero protection. At the other, C corporations give you maximum flexibility for raising capital but impose double taxation and rigid governance. In between, LLCs and S corporations trade a little more administrative work for real liability protection and better tax positioning.
The three consequences that separate them:
- Personal liability. Can creditors come after your house and personal bank accounts if the business fails or gets sued? In a sole proprietorship or general partnership, yes. In an LLC or corporation, generally no, provided you respect the entity’s separateness.
- Taxation. Is the business a separate taxpayer, or does its income flow to your personal return? Does self-employment tax apply to all of your earnings, or only to a salary portion?
- Paperwork and cost. State filing fees, annual reports, registered agents, meeting minutes, payroll processing. Some structures need almost none of this; others need all of it.
Changing your mind later can be cheap or ruinously expensive depending on the direction, which is why the initial choice matters more than most owners realize.
Sole Proprietorship and General Partnership
A sole proprietorship exists the moment you start doing business. There’s no formation filing, no state fee, and no legal distinction between you and the business. A general partnership works the same way when two or more people go into business together without filing any formal entity documents.
The simplicity is real, and so is the tradeoff. You carry unlimited personal liability for every dollar the business owes. If your partner signs a bad lease or a customer wins a lawsuit, creditors can pursue your personal accounts, your home, and anything else you own. That risk is the reason most owners outgrow this structure quickly.
Taxes are equally direct. Sole proprietors report business income and expenses on Schedule C of their personal Form 1040.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship) Partners report their shares on Schedule E.2Internal Revenue Service. About Schedule E (Form 1040), Supplemental Income and Loss Because the IRS treats you and the business as one taxpayer, you also owe self-employment tax. The combined rate is 15.3%, covering both the employer and employee portions of Social Security and Medicare, and it applies to 92.35% of your net self-employment income rather than the full amount.3Internal Revenue Service. Topic No. 554, Self-Employment Tax The Social Security portion (12.4%) stops applying once earnings exceed $184,500 in 2026, though the 2.9% Medicare portion has no cap.4Social Security Administration. Contribution and Benefit Base
This structure fits a side project with no employees, no debt, and no realistic litigation exposure. Anything more, and the liability exposure alone is usually worth the modest cost of forming an LLC.
Limited Liability Company
An LLC gives you a liability shield without forcing you into a corporate hierarchy. Members are generally not personally responsible for business debts or legal judgments against the company. If the LLC defaults on a commercial loan, lenders normally can only pursue the LLC’s assets, not the members’ personal property.
LLCs also offer a protection that corporations don’t: the charging order. When a member’s personal creditor wins a judgment, most states limit that creditor to a charging order, which entitles them to receive distributions that would have gone to the debtor-member but does not give them management rights, voting power, or access to the LLC’s assets. A court can often order the outright sale of corporate shares, so the LLC’s charging-order protection is a meaningful difference for owners worried about personal creditors.
How LLCs Get Taxed
The IRS has no dedicated tax category for LLCs. A single-member LLC is treated as a “disregarded entity,” meaning you report its income directly on your personal return the same way a sole proprietor does.5Internal Revenue Service. Single Member Limited Liability Companies A multi-member LLC defaults to partnership taxation, filing Form 1065 and issuing a Schedule K-1 to each member.6Internal Revenue Service. LLC Filing as a Corporation or Partnership Either type can elect to be taxed as a C corporation or an S corporation instead. That flexibility is why the LLC is the default recommendation for most small businesses: you get liability protection now, and you keep the option to change tax treatment as the business grows.
The Operating Agreement
An LLC’s internal rules live in its operating agreement, a private contract between members. The agreement specifies whether the LLC is member-managed (all owners participate in decisions) or manager-managed (designated individuals or outside professionals run operations). It also covers profit-sharing ratios, capital contributions, buyout procedures, and what happens if a member dies or wants to leave.
Skipping this document is one of the most common mistakes new owners make. Without an operating agreement, you default to your state’s LLC statute, which may divide profits equally regardless of who contributed what.
S Corporation Election
An S corporation is not a separate type of entity. It’s a tax election that an existing corporation or LLC makes with the IRS to have its income taxed on a pass-through basis instead of at the entity level.7Office of the Law Revision Counsel. 26 USC 1361 – S Corporation Defined The business pays no federal income tax. Profits and losses flow through to shareholders’ personal returns, avoiding the double taxation that burdens C corporations.
The main reason owners make the election: shareholder-employees can split their income between salary (subject to payroll taxes) and distributions (generally not subject to self-employment tax). For a profitable owner-operated business, that split can save thousands of dollars a year.
Eligibility Requirements
Not every business qualifies. The IRS requires that the corporation:
- Be a domestic corporation, organized under the laws of a U.S. state.
- Have no more than 100 shareholders (family members can sometimes be counted as one).
- Limit its shareholders to individuals, certain trusts, and estates; partnerships, other corporations, and nonresident aliens cannot hold shares.
- Issue only one class of stock, with every share carrying identical distribution and liquidation rights.8Internal Revenue Service. S Corporations
You elect S corporation status by filing Form 2553 with the IRS. The filing deadline is no later than two months and 15 days after the beginning of the tax year in which the election should take effect, or any time during the preceding tax year.9Internal Revenue Service. Instructions for Form 2553 – Election by a Small Business Corporation Miss the deadline and you either wait until next year or request late-election relief with a reasonable explanation.
The Reasonable Salary Trap
Here is where most S corporation owners get into trouble. Shareholder-employees must pay themselves a “reasonable salary” before taking additional profit as distributions. The salary is subject to standard payroll taxes; distributions above it generally are not.
The temptation to set a low salary and take the rest as distributions is obvious, and the IRS knows it. The agency evaluates reasonable compensation based on training, duties, time devoted to the business, and what comparable businesses pay for similar services.10Internal Revenue Service. S Corporation Compensation and Medical Insurance Issues Setting your salary at $30,000 when comparable work pays $85,000 is a red flag auditors recognize immediately.
C Corporation
A C corporation exists as a separate legal person, distinct from the people who own it. It has its own tax identification number, files its own return, and can sue or be sued in its own name. The separation provides strong liability protection, but it comes with governance you cannot skip: shareholders elect a board of directors, the board sets strategy and appoints officers, and the officers run daily operations. Skipping annual meetings, failing to keep minutes, or blurring personal and business finances gives a court reason to disregard the entity’s separate existence.
Double Taxation
A C corporation pays federal income tax at a flat 21% rate on its taxable income.11Office of the Law Revision Counsel. 26 USC 11 – Tax Imposed When after-tax profits are distributed as dividends, shareholders pay tax again. Qualified dividends are taxed at 0%, 15%, or 20% depending on the shareholder’s income.12Internal Revenue Service. Topic No. 404, Dividends and Other Corporate Distributions High earners face an additional 3.8% net investment income tax, pushing the effective maximum to 23.8%.13Internal Revenue Service. Topic No. 559, Net Investment Income Tax This two-layer system is the main reason most small businesses avoid C corporation status.
Profits that stay inside the corporation are only taxed at the 21% rate until they are eventually distributed. That makes the C corporation attractive for businesses planning to reinvest most of their earnings rather than pay them out.
Limited Partnership
A limited partnership splits owners into two categories. At least one general partner runs the business and accepts unlimited personal liability, the same as in a general partnership. Limited partners invest money but stay out of management, and their liability is capped at what they contributed. A limited partner who starts making management decisions risks losing that protection and being treated as a general partner.
Limited partnerships are common in real estate syndications, family wealth planning, and investment funds because they let passive investors participate without exposing their personal assets. For tax purposes, a limited partnership files Form 1065 and issues a Schedule K-1 to each partner.14Internal Revenue Service. Instructions for Form 1065 U.S. Return of Partnership Income Limited partners who remain passive generally do not owe self-employment tax on their share of income, which is a meaningful advantage over general partners.
Protecting the Liability Shield You Paid For
Forming an LLC or corporation creates a legal barrier between business debts and your personal assets. That barrier is not indestructible. Courts can “pierce the veil” and hold owners personally liable when the entity was treated as a shell rather than a genuinely separate business. The factors judges look at come down to one question: did you actually treat this business as its own thing?
The behaviors that most commonly trigger veil-piercing:
- Commingling funds — using the business account to pay personal expenses, or depositing business revenue into a personal account. The single biggest red flag.
- Undercapitalization — forming the entity without putting enough money into it to handle its normal obligations. Losing money over time is normal; never funding the entity adequately in the first place is not.
- Ignoring formalities — for corporations especially, failing to hold annual meetings, keep minutes, issue stock, or document major decisions.
- Using business assets for personal purposes — driving the company car for personal errands, living in company-owned property rent-free, or treating business equipment as your own.
Even hitting several of these factors usually isn’t enough on its own. Courts typically require a second finding: that failing to pierce the veil would produce an unjust result, such as a defrauded creditor. The practical lesson is simple. Keep separate bank accounts, maintain basic records, and fund the entity properly from the start.
Formation Costs and Ongoing Obligations
Every entity type except a sole proprietorship requires some level of government filing. The costs and administrative burdens vary by structure and state.
State Filing Fees
Forming an LLC or corporation means filing articles of organization (LLC) or articles of incorporation (corporation) with your state. Filing fees range widely, from roughly $35 to $500 depending on the state. Most states also charge recurring fees for annual or biennial reports, which can range from nothing in some states to over $800 when franchise taxes are included. These numbers shift, so check your secretary of state’s website before budgeting.
Employer Identification Number
Any business operating as a partnership, corporation, or multi-member LLC needs an Employer Identification Number from the IRS. The same applies if you hire employees or pay excise taxes.15Internal Revenue Service. Get an Employer Identification Number A sole proprietor with no employees can technically use a Social Security number, though many banks and vendors will still expect an EIN. There’s no fee, and applying online takes minutes.
Registered Agent
Every state requires LLCs, corporations, and partnerships to designate a registered agent: a person or service with a physical address in the state who accepts legal documents and government notices on the entity’s behalf. The agent must be available during normal business hours. You can serve as your own registered agent, but if you miss a delivery because you were out of town when a lawsuit was filed, you may not learn about it until a default judgment has already been entered. Commercial registered agent services typically cost $50 to $300 per year.
Beneficial Ownership Reporting
The Corporate Transparency Act originally required most domestic LLCs and corporations to report beneficial owners to the Financial Crimes Enforcement Network. As of March 2025, all entities formed in the United States are exempt from this reporting requirement.16Financial Crimes Enforcement Network. Beneficial Ownership Information Reporting The rule now applies only to foreign entities registered to do business in a U.S. state, which must file within 30 calendar days of receiving notice that their registration is effective. There is no filing fee.
Matching Structure to Your Plans
The right choice depends less on what you’re doing today and more on where you’re heading.
Raising Outside Investment
Venture capital firms and institutional investors almost always require a C corporation. C corporations can issue multiple classes of stock (preferred shares with liquidation preferences, common shares for founders), the governance rules are predictable, and shares transfer cleanly. An S corporation cannot issue preferred stock because of the one-class-of-stock rule. LLCs can achieve similar economic results through creative operating agreement drafting, but many investors and their lawyers find the structure unfamiliar compared to a standard Delaware C corp.
Small and Closely Held Businesses
Most small businesses with a few owners and no plans to seek venture funding land on either a plain LLC or an LLC that has elected S corporation tax treatment. The LLC provides liability protection and management flexibility; the S election lets owner-employees reduce self-employment tax by splitting income between salary and distributions. Keep in mind that the S election has restrictions. If you later want to bring in a foreign investor or a corporate co-owner, you’ll need to revoke the election or restructure.
Comparing the Tax Bills
The differences aren’t abstract. They determine how much of your revenue you keep.
- Sole proprietorship or general partnership: all net income is subject to both income tax and self-employment tax (15.3% on 92.35% of net earnings). No entity-level tax.17Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
- LLC (default): follows sole proprietorship or partnership rules depending on the number of members. Can elect S corp or C corp treatment for better tax positioning.
- S corporation: no entity-level tax. Only the shareholder-employee’s salary is subject to payroll taxes; distributions above that salary generally escape self-employment tax.
- C corporation: 21% corporate tax, then a second layer of tax when dividends reach shareholders (0%–23.8% including the net investment income surtax for high earners).
Congress created a Qualified Business Income deduction under Section 199A that allows owners of pass-through businesses to deduct up to 20% of qualified business income from taxable income. The deduction was originally available for tax years through December 31, 2025.18Internal Revenue Service. Qualified Business Income Deduction Legislative efforts to extend it beyond 2025 were underway as of early 2026, so check the current status before making entity decisions that hinge on it. When available, it substantially narrows the gap between pass-through taxation and the 21% corporate rate.
Operating Across State Lines
If your business has a physical presence or significant activity in a state other than where you formed the entity, that state will likely require you to register as a “foreign” entity. Foreign qualification involves filing paperwork (often called a certificate of authority), paying an additional filing fee, and appointing a registered agent in that state. Failing to register can result in fines and “door-closing” statutes that prevent your business from filing lawsuits in that state’s courts. Selling goods online to customers in other states generally does not trigger the requirement, but having an office, warehouse, or employees in another state usually does.
The Cost of Changing Later
Converting from a sole proprietorship or partnership to an LLC is relatively painless: file formation documents, get an EIN if you don’t have one, update contracts and bank accounts. Converting an LLC to a corporation can often be done tax-free under Section 351 of the tax code, which allows a contribution of assets for stock when the transferor controls at least 80% of the corporation afterward.
The expensive direction is the reverse. Converting a C corporation into an LLC or partnership triggers a deemed liquidation, meaning the corporation is treated as if it sold all its assets at fair market value and distributed the proceeds to shareholders. Both the corporation and the shareholders owe tax on the resulting gains. For a profitable, asset-heavy business, that can be devastating. It’s far cheaper to start with the right structure than to convert out of the wrong one. If there’s any realistic chance you’ll want pass-through taxation, start with an LLC and elect corporate treatment later if you need it, rather than incorporating first and trying to undo it.