S-Corp vs. LLC: The Core Question
When Illinois founders ask “should I be an S-Corp or an LLC?”, they’re usually asking the wrong question. An S-Corp is a tax election, not a separate legal entity type. You can have an LLC taxed as an S-Corp. Understanding what you’re actually choosing — and what problem you’re trying to solve — is the starting point.
What Is an LLC?
A Limited Liability Company (LLC) is a state-registered legal entity that separates your personal assets from business liabilities. By default, a single-member LLC is a “disregarded entity” for federal taxes (you report income on Schedule C), and a multi-member LLC is taxed as a partnership (income flows to members’ personal returns via K-1s).
Key features:
- Flexible ownership — any number of members, no restrictions on type
- Flexible management — member-managed or manager-managed
- No corporate formality requirements (no annual meetings required)
- Pass-through taxation by default
- Can elect S-Corp or C-Corp tax treatment
What Is an S-Corp?
An S-Corporation is a federal tax election — made by filing IRS Form 2553 — that allows a corporation (or LLC) to pass income through to shareholders while avoiding self-employment tax on a portion of that income. The “S” stands for Subchapter S of the Internal Revenue Code.
Key features:
- Pass-through taxation (no double taxation like a C-Corp)
- Owner-employees pay themselves a “reasonable salary” — subject to payroll taxes — then take remaining profits as distributions, which are not subject to self-employment tax
- Maximum 100 shareholders
- Shareholders must be U.S. citizens or permanent residents
- Only one class of stock permitted
The Key Tax Difference: Self-Employment Tax Savings
The primary reason profitable small businesses elect S-Corp status is to reduce self-employment tax. Here’s how it works:
As a single-member LLC (default), all net profit is subject to both income tax and self-employment tax (15.3% on the first ~$168,600 in 2026, 2.9% above that).
As an LLC taxed as S-Corp, the owner-employee takes a reasonable salary (subject to payroll taxes) and receives the remaining profit as a distribution — which is not subject to self-employment tax. The savings can be significant once the business is generating $50,000+ in annual net profit.
Example: $150,000 Net Profit
| Structure | Salary | Distribution | SE Tax |
|---|---|---|---|
| LLC (default) | N/A | $150,000 | ~$21,000 |
| LLC as S-Corp | $80,000 | $70,000 | ~$11,000 |
Estimated savings: ~$10,000/year. The actual number depends on your reasonable salary, state taxes, and additional administrative costs (payroll processing, S-Corp filing requirements).
When to Choose a Standard LLC
- You’re early-stage and not yet profitable enough for S-Corp savings to offset the added administrative burden
- You plan to raise venture capital (VCs typically require Delaware C-Corps)
- You have foreign investors or want more than 100 shareholders
- You want maximum flexibility in ownership structure
- You’re in a professional services business where your “reasonable salary” would consume most of the profit anyway
When the S-Corp Election Makes Sense
- Your LLC is generating $50,000+ in annual net profit
- You are an active owner-operator (the S-Corp savings require taking a salary)
- You don’t plan to raise institutional VC (S-Corp restrictions make that difficult)
- You’re comfortable with quarterly payroll tax filings and the added compliance cost
The Venture Capital Problem
If you’re building a startup that will raise institutional venture capital, the S-Corp path closes quickly. Most VC funds cannot hold S-Corp interests (fund LPs include foreign investors and tax-exempt entities — both ineligible S-Corp shareholders). Institutional investors will require conversion to a Delaware C-Corp before closing a round. Plan your entity structure around your fundraising path from day one.
See Fitter Law’s business formation services for Illinois startups and view our subscription plans for ongoing legal support.
Frequently Asked Questions
Can I convert my Illinois LLC to an S-Corp later?
Yes. You can make the S-Corp tax election at any time by filing IRS Form 2553. The election is typically effective for the tax year in which it’s filed if filed by March 15 (for calendar-year taxpayers). You don’t need to change your legal entity — just the tax treatment.
Does Illinois recognize S-Corp status?
Illinois conforms to the federal S-Corp election for income tax purposes but imposes its own 1.5% personal property replacement tax on S-Corp income. This is a cost that partially offsets the federal SE tax savings for some Illinois businesses.
Which is better for a solo consultant in Illinois?
At lower income levels, a standard LLC is simpler and sufficient. Once net profit consistently exceeds $60,000–$80,000, the S-Corp election typically makes financial sense — but run the numbers with your accountant first to account for Illinois-specific costs.