Table of Contents
Here’s what this guide covers, in order.
- The Most Common Business Organizations in the United States
- How to choose your small business entity
- Conclusion
- Frequently asked questions
The Most Common Business Organizations in the United States
Five business structures shape the sole proprietorship vs LLC for taxes decision for most US owners: the sole proprietorship, the general partnership, the LLC, the S corporation, and the C corporation. The IRS and the U.S. Small Business Administration recognize these same core types (SBA, “Choose a business structure”). One point matters more than any other. An S corporation is a tax election, not a legal entity. You don’t form an S corp at the state level. You form an LLC or a corporation, then elect S status with the IRS. Here’s the default federal picture for each, before any elections.
| Entity | Default federal tax | Personal liability | Formation |
|---|---|---|---|
| Sole proprietorship | Schedule C on Form 1040, 15.3% SE tax on net earnings | Unlimited. Owner and business are one legal person. | None. Automatic when one person starts business. |
| General partnership | Form 1065 plus Schedule K-1s, SE tax on active partners’ share | Unlimited, joint and several. | Automatic when two or more carry on business together. |
| LLC | Single-member disregarded (Schedule C, 15.3% SE tax). Multi-member defaults to partnership (Form 1065). | Limited. The LLC is a separate legal person. | File articles of organization with the state, pay a fee. |
| S corporation | Form 1120-S. Owner takes a W-2 salary plus distributions free of SE tax. | Limited, inherited from the LLC or corporation. | Elect via Form 2553 on an existing LLC or corporation. |
| C corporation | Form 1120, flat 21% rate. Dividends taxed again at the owner level. | Limited, the strongest separation. | File articles of incorporation, bylaws, issue stock. |
That 15.3% self-employment tax is the number entity choice actually moves, so it’s worth pinning down in 2026 terms (IRS, Self-employment tax).
- The rate is 15.3%, made of 12.4% for Social Security and 2.9% for Medicare.
- The 12.4% Social Security portion applies only up to the 2026 wage base of $184,500. Net earnings above that skip it.
- The 2.9% Medicare portion has no cap. An extra 0.9% applies above $200,000 for single filers and $250,000 for joint filers.
- SE tax starts once net earnings reach $400, and you can deduct one-half of it above the line.
A sole proprietor and a single-member LLC owner both pay this same 15.3% on net earnings. Neither structure escapes it on its own.
Sole Proprietorship
The sole proprietorship is the default the moment one person starts doing business. No state filing, no formation fee, no separate return. You report business profit on Schedule C of your Form 1040, and your net earnings face the 15.3% self-employment tax once they clear $400. The catch is liability. There’s no legal wall between you and the business, so a lawsuit or an unpaid debt reaches your personal assets directly. For the sole proprietorship vs LLC for taxes comparison, this is the baseline. Every other structure gets measured against the sole prop’s simplicity on one side and its full personal exposure on the other.
General Partnership
A general partnership forms automatically when two or more people carry on business together, with no state filing required. It files Form 1065 as an information return and issues a Schedule K-1 to each partner. Income passes through, so active partners owe self-employment tax on their share of the profit. Liability is the sharp edge here. It’s unlimited, and it’s joint and several, which means any one partner can be held responsible for the whole obligation, not just their slice. A partnership works when trust is high and assets are modest. Once real money or real risk enters the picture, most partners move to an LLC for the shield.
LLC
Here’s the part that surprises founders. A single-member LLC is a disregarded entity by default, taxed exactly like a sole proprietorship, same Schedule C, same 15.3% self-employment tax (IRS, single-member LLCs). A multi-member LLC defaults to partnership treatment on Form 1065. Either way, forming the LLC changes your legal exposure, not your federal tax math. What you gain is a liability shield, because the LLC is a separate legal person, plus flexibility. From an LLC you can later elect S-corp treatment with Form 2553, or C-corp treatment with Form 8832, without dissolving and starting over. That option to convert later is the LLC’s real value in the sole proprietorship vs LLC for taxes question.
S-Corporation
An S corporation is a tax election, not a legal entity. You don’t form one at the state level. You form an LLC or a corporation, then file Form 2553 with the IRS, generally no later than 2 months and 15 days after the start of the tax year you want it to take effect. The mechanics are what matter. The owner-employee takes a reasonable W-2 salary subject to payroll tax, then takes the remaining profit as distributions that aren’t subject to self-employment or payroll tax. That split is where the savings come from, once profit is high enough to support the salary. If you’re also weighing a C corporation, the difference between an S-corp and a C-corp comes down to pass-through taxation versus double taxation.
C-Corporation
A C corporation is a separate taxpayer. It files Form 1120 and pays a flat 21% corporate rate, then dividends to owners are taxed again at the individual level, the double taxation people warn about. For a profitable small business, that’s usually a disadvantage. For a company raising venture capital, it’s often mandatory. Institutional investors and standard stock-option plans generally require a C corporation, most often a Delaware C-corp, and QSBS treatment only exists at the C-corp level. So the C corporation isn’t a tax-savings move. It’s a funding-and-equity move, chosen when the cap table matters more than this year’s tax bill.
How to choose your small business entity
Choosing a small business entity is really two questions, not one. The legal question is how much liability protection you need. The tax question is what a structure costs you this year. Run them separately, then reconcile. Here’s a practical framework in five factors.
- Liability exposure. Do you sign contracts, carry inventory, hire people, or hold personal assets worth protecting? If yes, the shield of an LLC or corporation is worth the filing fee on its own (SBA, “Choose a business structure”). A sole proprietorship offers none.
- Tax cost today. At low profit, a single-member LLC and a sole proprietorship cost the same in federal tax. Form an LLC for protection and flexibility, not for a tax cut.
- Growth and funding plans. Raising venture money points to a C corporation, usually a Delaware C-corp. Bootstrapping or staying closely held favors a pass-through, which is almost always cheaper.
- Administrative burden. An S-corp adds payroll, a separate 1120-S return, and reasonable-compensation documentation. That overhead only pays off above a profit threshold.
- Ownership and investors. S corps cap at 100 shareholders, allow one class of stock, and bar most non-resident-alien and entity owners. LLCs and C corps are far more flexible.
Where the real tax savings live
Not in the LLC. In the S-corp election, made once profit is high enough to carry a reasonable salary. Under default pass-through treatment, all of your net profit faces the 15.3% self-employment tax. After electing S-corp status, you split the take into a reasonable W-2 salary, taxed like payroll, and distributions on the rest, which avoid self-employment and payroll tax. The saving is the 15.3% you no longer pay on the distribution portion, 2.9% above the Social Security wage base. That’s why the common rule of thumb is to consider the election once profit comfortably clears a reasonable salary, often cited in the $40,000 to $80,000+ range. The guardrail is reasonable compensation (IRS, S corporation compensation). You can’t zero out your salary to dodge payroll tax. Set it too low and the IRS can recharacterize distributions as wages and assess back taxes, penalties, and interest. A defensible number comes from comparables, not from thin air.
The 199A QBI deduction in 2026
The Section 199A qualified business income (QBI) deduction lets eligible pass-through owners deduct up to 20% of qualified business income. The 2017 Tax Cuts and Jobs Act created it, and the One Big Beautiful Bill Act, signed July 4, 2025, made it permanent (Tax Foundation, “The 199A Deduction and Pass-Through Business”). A few 2026 details drive the planning. The limits phase in around $201,750 for single filers and $403,500 for joint filers, and OBBBA widened those phase-in ranges to $75,000 and $150,000 respectively, which softens the cliff. New for 2026, there’s a minimum $400 deduction for taxpayers with at least $1,000 of QBI who materially participate. The subtle part is the interaction with an S-corp salary. QBI doesn’t include the W-2 wages you pay yourself, so a higher salary shrinks your QBI base, while a lower salary raises it but risks the reasonable-comp rule. Above the income thresholds, the deduction is also limited by W-2 wages paid, which can actually reward paying some salary. This is a genuine optimization problem, and indinero’s business tax services team runs it at your real numbers rather than by a rule of thumb.
The common path
Most growth-stage owners walk a predictable escalator. Sole proprietorship first, for its simplicity. Then a single-member LLC once there’s liability worth shielding. Then an S-corp election once profit clears a reasonable salary and the payroll-tax saving outweighs the added compliance. Then, if and when you raise venture capital, a C corporation, often by converting the LLC or S-corp into one. Each step is a response to a change in facts, not a permanent verdict. You’re not locked in. The structure that fits at $30,000 of profit is rarely the one that fits at $500,000, and the point of the framework above is to tell you when you’ve crossed the line.
Conclusion
The honest headline: a sole proprietorship and a single-member LLC are taxed identically by default. Same Schedule C. Same 15.3% self-employment tax. The LLC’s advantage is legal, a liability shield, and strategic, the option to elect S-corp treatment later. The tax savings people credit to “getting an LLC” actually come from the S-corp election once profit clears a reasonable salary, governed by the IRS reasonable-compensation rule and shaped by the now-permanent 199A deduction.
Entity choice isn’t a one-time event. The right structure at $30,000 of profit is often the wrong one at $150,000. Revisit it as profit, headcount, and funding change.
This is where indinero fits. Indinero is a CPA-led outsourced accounting, tax, and fractional CFO firm in continuous operation since 2009, and it serves the full range of growth-stage businesses, bootstrapped founders, PE-backed operators, LLCs, S-corps, and multi-entity groups, not just VC-backed C-corps. For an entity decision, the team runs the side-by-side tax projection at your actual profit, files the S-corp election on time via Form 2553, and sets a defensible reasonable salary you can support under audit. It also keeps the books clean so the liability shield actually holds, because a shield fails the moment personal and business finances get commingled. Clean books are also what give a founder real financial confidence, the difference between a structure that protects you and one that only looks like it does.
Get the structure right, keep it clean, and revisit it as you grow.
Frequently asked questions
Still weighing the sole proprietorship vs LLC for taxes decision at your own numbers? A handful of questions come up in almost every entity conversation, from when an S-corp election starts paying off to how the 2026 QBI deduction changes the math. The answers below cover the practical details founders raise most often when they reach this fork.
Is an LLC or a sole proprietorship better for taxes?
For federal taxes, a single-member LLC and a sole proprietorship are treated identically by default, so neither is inherently cheaper. Both report profit on Schedule C and both pay the 15.3% self-employment tax. An LLC buys a liability shield and the option to elect S-corp treatment later, not a lower tax bill. Indinero runs a side-by-side projection at your actual profit before you commit to a structure.
Do sole proprietors and single-member LLCs pay self-employment tax?
Yes, both sole proprietors and single-member LLC owners pay the 15.3% self-employment tax on net earnings once profit clears $400. That rate covers 12.4% for Social Security, capped at the 2026 wage base of $184,500, plus 2.9% for Medicare with no cap. Forming an LLC doesn’t remove this tax. The only structure that reduces it is an S-corp election, which indinero can model against your real numbers.
When should you switch from an LLC to an S corporation?
Consider an S-corp election once your LLC’s profit comfortably clears a reasonable salary, often cited in the $40,000 to $80,000 range. After electing, you take a reasonable W-2 salary taxed like payroll, then draw the rest as distributions free of self-employment tax. That split saves the 15.3% on the distribution portion. Indinero files the election on time via Form 2553 and sets a defensible salary you can support under audit.
Does an LLC protect your personal assets?
Yes, an LLC creates a liability shield because it’s a separate legal person, so lawsuits and business debts generally can’t reach your personal assets. A sole proprietorship offers none of this protection, since you and the business are one legal person. The shield only holds when you keep business and personal finances separate. Indinero keeps your books clean so commingling doesn’t quietly break the protection you formed the LLC to get.
Can you change your business entity or tax treatment later?
Yes, you can change your tax treatment later without dissolving, electing S-corp status via Form 2553 or C-corp status via Form 8832. An LLC gives you this flexibility, so you’re never locked into your first choice. Most growth-stage owners escalate over time, from sole proprietor to LLC to S-corp, then to a C corporation if they raise venture capital. Indinero revisits the structure as your profit, headcount, and funding change.
How does the 199A QBI deduction affect entity choice?
The Section 199A QBI deduction lets eligible pass-through owners deduct up to 20% of qualified business income, favoring LLCs and S-corps over C corps. Made permanent by the One Big Beautiful Bill Act in 2025, it interacts with your S-corp salary, since QBI excludes W-2 wages you pay yourself. A higher salary shrinks the deduction, while a lower one risks the reasonable-comp rule. Indinero’s tax team runs this at your real numbers, not a rule of thumb.
