Sole Proprietorship vs. LLC vs. S Corp for a Small Business

9/29/2026

For a business with one owner, "sole proprietorship vs. LLC vs. S corp" sounds like a choice among three options. It is really a path with two separate steps, and each step answers a different question.

Sole proprietorship to single-member LLC is a legal It changes liability protection and state filing obligations. For federal income tax, nothing changes: a single-member LLC is disregarded by default and the owner keeps filing Schedule C.
Single-member LLC (or sole proprietorship) to S corporation is a tax It changes how the owner is paid, which taxes apply to which dollars, and what compliance the business must keep up.

Keeping those two steps apart clears up most of the confusion clients bring to this conversation. This page works through each step for a single owner, shows an illustrative break-even calculation, lists the costs that go with an S election, and flags the state-level items that can change the answer.

Step Zero: The Sole Proprietorship

A sole proprietorship is simply an individual doing business without forming an entity. The tax mechanics:

Income and expenses go on Schedule C of the owner's Form 1040.
Net earnings are subject to self-employment tax on Schedule SE: 12.4% Social Security up to the annual wage base ($184,500 for 2026) and 2.9% Medicare on everything, computed on 92.35% of net profit. The 0.9% Additional Medicare Tax applies above the threshold for the owner's filing status.
Half of the SE tax is deductible in arriving at adjusted gross income.
The owner may qualify for the Section 199A deduction on qualified business income. The One Big Beautiful Bill Act made it permanent at 20% and added a minimum deduction for owners with at least a modest amount of QBI from active businesses.
There is no payroll for the owner. The owner draws money as needed; draws are not deductible and not taxed separately.

The simplicity is real. There is one return, no separate entity filing, no payroll for the owner and no entity-level state taxes in most states. The disadvantage is legal, not tax: the owner is personally liable for the business's obligations.

Step One: Forming a Single-Member LLC

Forming an LLC creates a separate legal entity under state law. Properly maintained, it can shield the owner's personal assets from the business's debts and claims (though not from the owner's own professional negligence, and not from obligations the owner personally guarantees).

For federal income tax, a single-member LLC is disregarded by default. The owner still files Schedule C, still pays SE tax and still takes draws. The IRS treats the LLC and its owner as one taxpayer for income tax. (For employment and certain excise taxes, a disregarded LLC with employees is treated as a separate entity, which matters once the business hires.)

What forming the LLC does change:

State fees and filings. Formation fees, annual reports and, in some states, an annual LLC tax or fee regardless of profit. California is the well-known example: an LLC doing business there owes an $800 annual tax, plus an LLC fee once its California total income reaches the fee threshold.
Banking and records. The LLC needs its own bank account, and commingling personal and business funds can undermine the liability protection the LLC was formed to provide.
Contracts and titles. Leases, vendor contracts, licenses and insurance should be in the LLC's name.
The W-9 the business gives its customers. A disregarded LLC gives the owner's classification and TIN, so customers who issue 1099s still issue them to the owner.

The LLC step is often worth it for liability reasons alone, but it should not be sold to a client as a tax saving. It is not one.

Step Two: Electing S Corporation Status

An LLC (or a newly formed corporation) can elect S status by filing Form 2553. For an LLC, that one form makes it a corporation for tax purposes and an S corporation at the same time. From the effective date:

The business files Form 1120-S and gives the owner a Schedule K-1.
The owner becomes an employee for the services they perform and must be paid reasonable compensation through payroll, with income tax withholding and FICA.
Profit above that salary passes through on the K-1 and is generally not subject to FICA or SE tax. That is the saving.
Distributions replace draws, and they must be pro rata if there is ever more than one shareholder.

The election is where the tax effect lives, so it is where the modeling has to happen.

An Illustrative Break-Even

There is no profit level at which an S election becomes correct for every owner. The figures below are an illustration only, using a single owner with $150,000 of net profit before owner compensation and an assumed reasonable salary of $80,000. The right salary depends on the owner's actual duties, time and market pay for the role; it is not a percentage of profit.

	Schedule C (sole prop or SMLLC)	S corporation
Amount subject to SE tax / FICA	$138,525 (92.35% of $150,000)	$80,000 salary
SE tax / combined FICA at 15.3%	about $21,194	about $12,240
Gross employment tax difference		about $8,954 lower

That $8,954 is the number clients hear about. It is not the number they keep. Before recommending the election, subtract or adjust for:

Payroll administration. A payroll service, quarterly Form 941s, an annual Form 940, Form W-2 and W-3, and state withholding and unemployment filings.
Federal and state unemployment tax on the owner's wages, where the state treats the owner-employee as covered. Treatment of corporate officers and owner-employees for state unemployment varies.
Workers' compensation, where the state requires or the owner elects coverage for themselves.
The Form 1120-S and any state S corporation return, which typically cost more to prepare than a Schedule C.
State entity-level taxes. California, for example, taxes S corporations at 1.5% of California net income, subject to the $800 minimum franchise tax.
The QBI deduction. The owner's salary is not qualified business income, so moving $80,000 of profit into wages reduces the base for the 199A deduction. For owners above the income thresholds, the wages the S corporation pays can instead help them qualify for the deduction. Model both.
Retirement contributions. In an S corporation, plan contributions for the owner are based on W-2 wages. A low salary can cap a solo 401(k) or SEP contribution well below what the same profit supported on Schedule C.
Future Social Security benefits, which are based on earnings subject to Social Security tax. A lower salary means lower credited earnings. For some owners that trade-off matters.

In many real cases, those costs consume a large part of the gross saving at lower profit levels, and the election begins to make clear sense only when profit is comfortably above a defensible salary and the costs above. That is a general direction, not a threshold. Run the numbers for the client.

When the S Election Is Usually Not Worth It

Profit is close to what a reasonable salary for the owner's work would be. If most of the profit has to be paid as wages, there is little left to pass through free of FICA.
The owner wants to maximize retirement contributions and would need a high salary to do it.
The business expects losses, especially losses funded by debt the owner does not lend personally; a Schedule C loss offsets other income without the S corporation's basis limits.
The state or city adds entity-level costs that offset the saving. New York City, for example, does not recognize the S election and applies its general corporation tax to S corporations.
The owner will not run payroll. An S corporation whose owner takes only distributions and no salary is exposed to recharacterization of those distributions as wages, with back employment taxes, penalties and interest.

When It Usually Is

A service business with steady profit well above a defensible salary for the owner.
An owner who will actually run payroll on schedule and keep corporate records.
A business without plans for investors that S status cannot accommodate.
An owner whose state treats S corporations favorably or at least neutrally.

Practical Items When Moving From Schedule C to an S Election

Timing. The election is due no more than 2 months and 15 days after the start of the tax year it should apply to, or at any time in the preceding year. For a calendar-year LLC that wants S treatment from January 1, that generally means by March 15. A mid-year effective date for a new entity is possible but splits the owner's year between Schedule C and the S corporation.

Payroll from the first month. The most common first-year failure is an owner who keeps taking draws all year and then needs a large December payroll. Our post on payroll for an S corp election covers the registrations and the reasonable compensation documentation to put in place before the first pay date.

Health insurance. For a more-than-2% shareholder, health insurance premiums paid by the S corporation are included in the owner's W-2 wages (not subject to Social Security and Medicare tax when paid under a qualifying plan), and the owner may be able to take the self-employed health insurance deduction. Set this up correctly in the first payroll year, not at year-end.

Expense reimbursements. Owners who paid business expenses personally as sole proprietors simply deducted them on Schedule C. As employees of their S corporation, they should be reimbursed under an accountable plan so the reimbursement is deductible to the corporation and not wages to the owner.

Retirement plan review. If the owner has a SEP or solo 401(k) based on Schedule C earnings, revisit it. Contributions after the election are measured on W-2 wages. Our comparison of SIMPLE IRA vs. SEP IRA vs. 401(k) covers the plan choices.

State registrations. Withholding, unemployment, and any state S corporation election or entity-level tax. Check whether the state requires its own election; most follow the federal election, but not all.

Year-end planning. The first year after an election is a good time for a mid-year projection, so the owner's salary, estimated payments and retirement contributions line up before December. Our year-end tax planning for small businesses post covers the levers.

A Simple Way to Present the Options

When a single-owner client asks which to choose, three plain questions settle most of it:

Do you need liability protection? If yes, form an LLC. This does not change your federal income tax.
Is your profit comfortably above what you would have to pay yourself as a reasonable salary? If not, stay on Schedule C.
If it is, will the saving survive payroll costs, state taxes, the QBI change and your retirement plans? Model it. If it does, elect S status and run payroll from the first month.

The answer can change over time. Many businesses start as sole proprietorships, form an LLC once they have contracts and employees, and elect S status once profits grow. That sequence is normal, and it is easier to advise on when the client understands that only the last step is a tax decision.

Learn the Sole Proprietor Side Thoroughly

Most entity decisions for small businesses start from a Schedule C, and many of the mistakes start there too: mixed personal and business expenses, missed SE tax planning and estimated payment problems. Our Sole Proprietorship course covers the sole proprietor side of this path. For the S corporation side, see our S Corporations course.

Frequently Asked Questions

What is the difference between a sole proprietorship, an LLC and an S corp?

A sole proprietorship is an individual doing business without a separate entity. An LLC is a state-law entity that provides liability protection; a single-member LLC is disregarded for federal income tax by default, so it is taxed the same as a sole proprietorship. An S corporation is a tax status that a corporation or LLC elects by filing Form 2553. It requires the owner to take a reasonable salary through payroll, and profit above that salary is generally not subject to self-employment tax.

Is a single-member LLC better than an S corp?

They answer different questions. A single-member LLC provides liability protection but does not change federal income tax. An S election can reduce employment taxes once profit is comfortably above a reasonable salary for the owner, but it adds payroll, a separate return and sometimes state entity taxes. Many owners have both: an LLC for liability purposes that has elected S corporation taxation once the numbers justify it.

At what income does an S corp make sense?

There is no single figure. The saving depends on how much of the profit has to be paid as reasonable salary, and the costs include payroll administration, a corporate return, state taxes and possible reductions in the QBI deduction and retirement contributions. In an illustrative case with $150,000 of profit and an $80,000 salary, the gross employment tax difference is about $8,954 before those costs. Model the client's own numbers before recommending an election.

Does forming an LLC save taxes?

Not by itself at the federal level. A single-member LLC is disregarded by default, so the owner keeps filing Schedule C and paying self-employment tax exactly as a sole proprietor does. Some states impose annual LLC taxes or fees, so forming an LLC can increase costs. The tax change comes only if the LLC elects to be taxed as an S corporation (or a C corporation).

Do I have to pay myself a salary in an S corp?

Yes, if you perform services for the business. Compensation for those services must be paid as wages through payroll, with withholding and FICA, and it must be reasonable for the work you do. Taking only distributions exposes the business to having those distributions recharacterized as wages, with back employment taxes, penalties and interest. Set the salary and document how it was determined before the first payroll.

Can a sole proprietor elect S corp status?

Not directly. A sole proprietorship is not an entity, so it has nothing to elect. The owner first forms an entity, usually an LLC or a corporation under state law, transfers the business to it, and then files Form 2553 for the entity. An LLC that files Form 2553 is treated as a corporation as of the election's effective date and does not need a separate Form 8832.