Choosing between an S-corp and a sole proprietorship comes down to one question: does the self-employment tax you save by paying yourself a salary plus distributions outweigh the cost of running payroll and filing a separate corporate return? A sole proprietor pays the full 15.3% self-employment tax on nearly all business profit. An S-corp owner pays FICA only on a W-2 salary, and takes the rest as distributions that skip payroll tax entirely. The savings are real, but they only start to matter above roughly $75,000 to $100,000 in net profit, and the IRS polices how low that salary can go.
The Tax Difference That Drives the Decision
As a sole proprietor, you report income and expenses on Schedule C, which flows to your Form 1040.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship) Net profit is subject to income tax and to self-employment tax at 15.3%, which breaks into 12.4% for Social Security and 2.9% for Medicare.2Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes) The tax is calculated on 92.35% of net earnings. The Social Security portion applies only up to the wage base ($184,500 for 2026), while the Medicare portion has no cap.3Social Security Administration. Contribution and Benefit Base Net self-employment income above $200,000 for single filers or $250,000 for joint filers picks up an additional 0.9% Medicare surtax.4Internal Revenue Service. Topic No. 560 – Additional Medicare Tax You can deduct half of your self-employment tax as an adjustment to income, which lowers your income tax but not the SE tax itself.5Internal Revenue Service. Topic No. 554 – Self-Employment Tax
An S-corporation does not pay federal income tax at the entity level. Income passes through to shareholders on Schedule K-1 and shows up on their personal returns.6Internal Revenue Service. Shareholder’s Instructions for Schedule K-1 (Form 1120-S) The owner-employee splits compensation into two streams. The W-2 salary is subject to the full 15.3% in FICA, split evenly between the employee and the S-corp at 7.65% each.7Social Security Administration. Social Security and Medicare Tax Rates The remaining profit, taken as a distribution, is subject to income tax but escapes FICA and self-employment tax.
What that means in dollars: on $150,000 of net profit, an S-corp owner paying a $70,000 salary owes roughly $10,710 in combined FICA on the salary. The $80,000 taken as a distribution pays no payroll tax at all, a savings of about $12,240 compared to a sole proprietor paying self-employment tax on the full amount. The real-world gap is somewhat smaller after applying the sole proprietor’s half-SE-tax deduction and the 92.35% multiplier, but the direction is the same.
Liability and the Underlying Entity
A sole proprietorship is not a filing. It exists automatically when you start selling goods or services without forming a separate entity, aside from any local business licenses.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship) The trade-off is total personal exposure. You and the business are the same legal person, so every business debt, contract, and lawsuit judgment can reach your personal bank accounts, home equity, and other assets.
An S-corporation is not actually an entity type. It is a tax election layered on top of a corporation or LLC formed under state law. You file articles of incorporation or organization, which typically costs $50 to $500 depending on the state, and that filing creates a legal entity separate from you. That separation is the source of the liability shield. Once the entity exists, you elect S-corp tax treatment by filing IRS Form 2553.8Internal Revenue Service. Instructions for Form 2553
Limited liability is not automatic once the entity is on file. If you commingle personal and business funds, skip required corporate formalities, or personally guarantee a business loan, a court can pierce the veil and hold you personally responsible. The entity has to function like an entity, not just exist on paper.
The Reasonable Compensation Rule
The salary-and-distribution split invites an obvious game: pay yourself almost nothing and take everything as tax-free distributions. The IRS knows this, and it is the most common audit trigger for S-corporations.9Internal Revenue Service. S Corporation Employees, Shareholders and Corporate Officers
Any shareholder who performs more than minor services must receive reasonable compensation as W-2 salary. The standard is what a comparable business would pay a non-owner employee for similar work.10Internal Revenue Service. Wage Compensation for S Corporation Officers Courts have consistently backed the IRS on this. In one well-known case, an accounting firm’s owner paid himself $24,000 while the S-corp earned significantly more, and the court reclassified distributions as wages, triggering back FICA taxes plus interest and penalties.
The IRS and courts weigh the volume and complexity of the business, the owner’s duties and expertise, comparable salaries in the same industry and geography, and what the business pays other non-owner employees. Industry salary surveys are the best evidence for a defensible number. As a rough IRS internal benchmark, officer compensation above 10% of gross revenue at the 90th percentile raises fewer flags for mid-size businesses, though results vary widely by industry.11Internal Revenue Service. Reasonable Compensation Job Aid for IRS Valuation Professionals Document the analysis before you set the salary, not after an audit notice arrives.
The QBI Deduction Offset
The qualified business income deduction lets eligible owners deduct up to 20% of qualified business income, and it treats the two structures differently.12Internal Revenue Service. Qualified Business Income Deduction Originally set to expire after 2025, the deduction was made permanent by the One Big Beautiful Bill Act, signed into law in July 2025, with changes effective for tax years beginning after December 31, 2025.
For a sole proprietor, Schedule C net profit generally qualifies as QBI, and 20% comes off the top. For an S-corp owner, the W-2 salary is explicitly excluded from QBI. Only the distribution counts, so the QBI base is smaller and the deduction is smaller.
Applying that to the $150,000 example: a sole proprietor’s QBI deduction is based on roughly $150,000, yielding a $30,000 deduction. An S-corp owner taking a $70,000 salary has QBI of roughly $80,000, yielding a $16,000 deduction. At a 22% marginal rate, that $14,000 gap costs about $3,080 more in income tax. The S-corp still wins on net, but by less than the raw self-employment tax savings suggest.
For 2026, the income limitations that restrict the deduction for higher earners and specified service businesses fully phase in at approximately $544,600 for married couples filing jointly and $272,300 for other filers. Below those thresholds, most owners take the full 20% deduction without hitting the W-2 wage or capital limitations. The new law also added a $400 minimum deduction for taxpayers with at least $1,000 in QBI from a business in which they materially participate.
What an S-Corp Actually Costs to Run
The gap in administrative overhead is large enough to affect the decision as much as the tax math.
A sole proprietor’s federal tax obligations are Schedule C and Schedule SE filed with Form 1040. No separate business return. You need clean records and, as a practical matter, a separate business bank account, though it is not legally required. Both sole proprietors and S-corp owner-employees generally need to make quarterly estimated tax payments to avoid underpayment penalties. For 2026, the safe harbor requires paying at least 90% of current-year tax or 100% of prior-year tax (110% if prior-year AGI exceeded $150,000).13Internal Revenue Service. 2026 Form 1040-ES – Estimated Tax for Individuals
The S-corp adds several mandatory layers. You must run formal payroll for your salary, which means calculating and withholding federal and state income taxes plus the employee’s share of FICA, depositing withholdings on the IRS schedule, and filing Form 941 every quarter.14Internal Revenue Service. About Form 941 – Employer’s Quarterly Federal Tax Return At year-end, you issue yourself a W-2. Most S-corp owners use a payroll service, typically $40 to $60 per month for one employee.
The S-corp also files its own federal return, Form 1120-S, due March 15 for calendar-year corporations.15Internal Revenue Service. About Form 1120-S – U.S. Income Tax Return for an S Corporation Professional preparation typically runs $800 to $2,500, versus a few hundred for a Schedule C. Late filing penalties are $255 per shareholder for each month or partial month the return is overdue, up to 12 months, assessed even if no tax is due.16Internal Revenue Service. Instructions for Form 1120-S
If the underlying entity is a corporation rather than an LLC, state law may require formal governance: annual shareholder and director meetings, written minutes, and resolutions for major decisions. Most states also require annual or biennial reports with the secretary of state, typically $9 to $150.
When the S-Corp Starts to Pay Off
The election saves money only when self-employment tax savings on distributions exceed the added compliance costs. For most small businesses, all-in annual overhead for payroll processing, the corporate return, and bookkeeping runs $2,000 to $4,500.
That sets a rough income floor:
- Below $50,000 in net profit, potential SE tax savings are small enough that compliance costs eat most or all of them.
- Between $50,000 and $75,000, the math is close and depends heavily on what salary is defensible in your industry.
- Above $75,000 to $100,000, the S-corp election usually produces meaningful net savings.
- At $150,000 or more, annual tax savings after compliance costs often exceed $5,000.
Remember the QBI offset. Paying yourself a salary shrinks your QBI base and claws back some of the SE tax savings through a smaller deduction. Modeling both scenarios with actual numbers is worth the cost of a tax professional before you make the election.
S-Corp Eligibility Restrictions
Not every business qualifies. The IRS imposes specific requirements under 26 U.S.C. ยง 1361, and violating any of them terminates the election automatically, converting the entity to a C-corporation, which pays its own income tax and can result in double taxation of profits.17Office of the Law Revision Counsel. 26 USC 1361 – S Corporation Defined
- The business must be a domestic corporation or a domestic LLC electing corporate treatment.
- No more than 100 shareholders. Family members can elect to be treated as a single shareholder.
- Shareholders must be U.S. citizens or resident aliens, certain qualifying trusts, or estates. Partnerships, other corporations, and nonresident aliens cannot hold shares.
- Only one class of stock, though shares can carry different voting rights as long as economic rights are identical.
A sole proprietorship has none of these constraints, but it is inherently limited to a single owner. Bring in a partner and the business becomes a partnership by default. If you plan to take on investors, add foreign co-owners, or issue different classes of equity, the S-corp restrictions may push you toward a C-corporation or a partnership structure.
A handful of states either do not automatically recognize the federal S-corp election or impose their own entity-level taxes on S-corporations. Check your state’s rules before assuming the federal election is all you need.
How to Elect S-Corp Status
Most businesses that elect S-corp status start as either a sole proprietorship or a default LLC. The typical path: form an LLC under state law, then file Form 2553 with the IRS. For an existing sole proprietorship, you would first form the LLC or corporation, transfer the business assets, and then make the election.
Form 2553 must be filed no later than two months and 15 days after the beginning of the tax year you want the election to take effect, or at any time during the preceding tax year.8Internal Revenue Service. Instructions for Form 2553 Every shareholder must consent. Miss the deadline and you either wait until the next tax year or apply for late-election relief under IRS Revenue Procedure 2013-30, which requires showing reasonable cause and consistent S-corp treatment on all returns filed since the intended effective date.18Internal Revenue Service. Revenue Procedure 2013-30 – Relief for Late S Corporation Elections The late-relief request must be made within three years and 75 days of the intended effective date.