What is the difference between an LLC and S-Corp for taxes?
A single-member LLC defaults to sole proprietor taxation (all profit subject to self-employment tax). An S-Corp (or an LLC with an S-Corp election) allows owners to pay themselves a reasonable salary and take remaining profits as distributions not subject to self-employment tax, potentially saving thousands.
Detailed Explanation
The choice between an LLC and an S-Corp is one of the most important tax decisions for US small business owners. Both structures provide liability protection, but they are taxed very differently, and the right choice depends on your profit level and personal situation.
How a default LLC is taxed
A Limited Liability Company (LLC) is not a tax entity under federal law — the IRS ignores it and taxes the owner directly: - Single-member LLC: treated as a sole proprietor. All net profit flows to Schedule C of your Form 1040 and is subject to both income tax AND self-employment tax (15.3% on the first $168,600 of net earnings in 2024, then 2.9% Medicare on amounts above this). - Multi-member LLC: treated as a partnership. Each member's share of profit flows through on Schedule K-1 and is generally subject to self-employment tax.
With a default single-member LLC earning $150,000 profit, you would pay approximately $21,198 in self-employment tax (15.3% x $138,437, which is 92.35% of $150,000, the SE tax adjustment).
How an S-Corp is taxed
An S-Corporation is a pass-through entity: profits flow through to shareholders and are reported on personal tax returns. The key difference from an LLC is how the income is categorised: - The owner-employee must receive a reasonable salary, which is subject to payroll taxes (FICA: 7.65% employee share + 7.65% employer share = 15.3% total) - Remaining profits can be distributed as owner distributions, which are not subject to self-employment tax or FICA
With the same $150,000 profit split as $70,000 salary + $80,000 distribution, FICA applies only to the $70,000: approximately $10,710 in payroll taxes. The $80,000 distribution avoids FICA entirely, saving approximately $10,488 compared to the single-member LLC approach.
The reasonable compensation requirement
The IRS requires S-Corp owner-employees to pay themselves a reasonable salary before taking distributions. If you pay yourself an unreasonably low salary ($1 salary and $149,999 distribution), the IRS can reclassify distributions as wages and assess back payroll taxes, penalties, and interest. The reasonable salary should reflect what the market would pay for the services you provide.
The LLC S-Corp election
An LLC does not have to incorporate as a C-Corp to get S-Corp tax treatment. An existing LLC can file Form 2553 with the IRS to elect S-Corp tax status. The LLC remains an LLC for state law purposes (liability protection, operating agreement, member structure) but is taxed as an S-Corp federally. This is the most common structure for small businesses that want S-Corp tax benefits without the formality of a corporation.
The election must generally be filed by March 15 of the tax year you want it to take effect (or within 75 days of forming the entity). Late elections are sometimes allowed.
When the S-Corp election makes sense
The S-Corp election generally makes sense when: - Net profit (after reasonable salary) is $40,000 or more per year - The payroll tax savings exceed the added costs of running payroll (payroll software, accountant fees, quarterly payroll filings) - You are willing to run formal payroll with W-2s, quarterly 941 filings, and year-end W-3 filing
At lower profit levels, the cost of payroll administration may exceed the SE tax savings.
S-Corp vs C-Corp
An S-Corp passes through income to shareholders (no corporate-level federal income tax). A C-Corp pays corporate tax on profits (21% federal rate in 2024) and shareholders pay personal tax on dividends — double taxation. Most small businesses avoid C-Corp status for this reason unless they plan to reinvest profits rather than distribute them, seek venture capital, or want to offer certain employee benefits.
State tax treatment
State treatment of LLCs and S-Corps varies. Some states charge additional franchise taxes, LLC fees, or do not recognise S-Corp elections for state income tax. California, for example, charges an $800 minimum franchise tax plus an LLC fee based on gross receipts. Always verify state-level implications when choosing your entity structure.
Source: IRS S Corporation Tax Centers
Real-World Examples
Consultant saving on SE tax with S-Corp election
A marketing consultant has $200,000 net profit. As a single-member LLC, she pays approximately $28,480 in SE tax. With an S-Corp election, she pays herself $90,000 salary (reasonable for her services) and takes $110,000 as an S-Corp distribution. She pays FICA on $90,000 ($13,770) and zero SE tax on the $110,000 distribution. Savings: approximately $14,710 per year, easily justifying the cost of payroll.
Low-profit business better off as default LLC
A part-time virtual assistant earns $28,000 net profit. As a single-member LLC, SE tax is approximately $3,957. With an S-Corp election, she would need to run formal payroll and file quarterly 941s — monthly payroll software and accountant fees could easily cost $2,400/year, leaving minimal net benefit from the S-Corp election.
Common Mistakes to Avoid
- Paying yourself an unreasonably low S-Corp salary to maximise distributions — the IRS audits this specifically and will reclassify distributions as wages, triggering back payroll taxes and penalties.
- Making an S-Corp election without setting up payroll — distributions without a corresponding salary are a red flag to the IRS and can void the SE tax savings.
- Not considering state-level taxes when choosing between an LLC and S-Corp — some states have high LLC fees or do not honour the S-Corp election for state income tax.
- Waiting too long to make the S-Corp election — Form 2553 must generally be filed by March 15 of the relevant tax year or within 75 days of entity formation.
Frequently Asked Questions
Does an LLC have to become a corporation to elect S-Corp status?
No. An existing LLC can file IRS Form 2553 to be taxed as an S-Corp without changing its legal structure under state law. The LLC remains an LLC for all non-tax purposes (liability protection, management structure, operating agreement) and is simply taxed as an S-Corp at the federal level. This is the most common approach for small businesses.
What is the self-employment tax rate for 2024?
The self-employment tax rate is 15.3% on the first $168,600 of net SE income in 2024 (12.4% Social Security plus 2.9% Medicare). Above $168,600, you pay only the 2.9% Medicare portion. Additionally, income over $200,000 (single) or $250,000 (married filing jointly) is subject to an additional 0.9% Medicare surtax. You can deduct 50% of your SE tax as a business expense.
What are the filing requirements for an S-Corp?
S-Corps must file Form 1120-S annually (due March 15, with a 6-month extension available). They must provide K-1 forms to all shareholders. Owner-employees must run payroll, file quarterly Form 941, pay FUTA taxes, and issue W-2s. S-Corps cannot have more than 100 shareholders, only one class of stock, and shareholders must be US citizens or permanent residents.
Can I switch back from an S-Corp election?
Yes, but revocation or termination of S-Corp status is subject to restrictions. You generally cannot re-elect S-Corp status for 5 years after the election is terminated (unless the IRS consents). Before making an S-Corp election, ensure it is a long-term fit for your business.
Practical Tips
- Run a break-even analysis before making an S-Corp election: compare the SE tax savings (roughly 15.3% of the distribution amount) against the annual cost of payroll administration (software, accountant, time).
- Document your reasonable salary determination with market data (comparable salaries in your industry and location) — having a written rationale protects you if the IRS questions your compensation level.
- Set up quarterly estimated tax payments for both your salary withholding and the income tax on S-Corp distributions to avoid underpayment penalties.
- Review your entity structure annually with a CPA — as your business grows or your personal situation changes, the optimal tax structure may shift.
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