If you started making money on your own this year and never filed a single form, the IRS has already classified you. You are a sole proprietor, the default structure for anyone doing business alone. That is not a problem, and for millions of people it is exactly the right fit. But somewhere between your first sale and your first serious year of profit, the question comes up: should this become an LLC, or even an S-corp?
The answer matters because the structure you pick controls three things: how much paperwork you do, who can come after your personal assets, and how your profit gets taxed. The good news is the plain-English version fits in one article. The IRS lays out the tax side of each option on its business structures page, and the Small Business Administration walks through the legal side in its choose-a-structure guide.
Sole proprietor: the default, and the simplest
A sole proprietorship is not something you form. It is what you are the moment you do business by yourself without registering an entity. You and the business are legally the same person. Income goes on Schedule C of your personal tax return, you pay self-employment tax on the net profit, and there is no separate business return to file.
The simplicity cuts both ways. Because you and the business are the same, business debts and lawsuits are your debts and lawsuits. If a customer sues or a vendor goes unpaid, your personal savings, car, and in some states your home can be on the table. For a low-risk side income, many people accept that trade. For a business with employees, contracts, or physical risk, it gets uncomfortable fast.
LLC: a legal shield, not a tax category
A limited liability company is a state-level legal wrapper. You form it by filing paperwork with your state, usually the secretary of state’s office, and paying a filing fee that varies widely by state. The point of the wrapper is in the name: if the business is sued or cannot pay its debts, your personal assets are generally protected, as long as you keep business and personal finances separate and respect the formalities.
Here is the part that surprises people: an LLC is not a tax status. The IRS does not have an LLC tax return. By default, a one-owner LLC is taxed exactly like a sole proprietorship (the IRS calls it a disregarded entity), and a multi-owner LLC is taxed like a partnership. Forming an LLC changes your legal protection, not your tax bill. Your Schedule C, your self-employment tax, all of it stays the same unless you take the next step.
S-corp: a tax election, not a company type
An S-corporation is not a thing you form at the state, either. It is a tax election you make with the IRS, usually by filing Form 2553, and an LLC or corporation can both make it. The IRS explains the requirements on its S-corporation page: a domestic entity, no more than 100 shareholders, one class of stock, and shareholders who are generally individuals, not other companies.
Why bother? Self-employment tax. A sole proprietor or default LLC owner pays Social Security and Medicare tax on the entire net profit. An S-corp owner who works in the business must be paid a reasonable salary, and payroll taxes apply to that salary, but profit distributed beyond the salary is not subject to self-employment tax. On a healthy profit, that split can save real money. The IRS polices the word reasonable, though: paying yourself a token salary and calling everything else a distribution is a well-known audit trigger.
What the S-corp costs you in hassle
The savings are not free. An S-corp files its own tax return (Form 1120-S) every year, runs actual payroll with withholding and quarterly filings, and issues you a W-2. That usually means paying for payroll software or a bookkeeper. Many accountants suggest the election starts to pay for itself somewhere north of a solid full-time profit, but the break-even depends on your state, your salary, and what you pay for the extra administration. Run the numbers before you leap.
How to think about the upgrade path
A practical sequence that fits most people: start as a sole proprietor while the income is small and the risk is low. Form an LLC when you have something to protect, meaning meaningful assets, contracts, clients on your premises, or anyone working for you. Consider the S-corp election only when profits are consistently large enough that the self-employment tax savings clearly beat the extra bookkeeping.
Two more notes worth pinning. First, none of these choices are permanent. A sole proprietor can form an LLC next month, and an LLC can elect S-corp treatment in a later year. Second, structure is not a substitute for basics: an LLC that mixes personal and business money in one account can lose its liability shield in court, a doctrine lawyers call piercing the veil. Whatever you choose, open a separate account, keep clean records, and revisit the decision once a year when you see the profit line. The structure should follow the business, not the other way around.
