LLC vs S-Corp: which one, when, and why they aren't the same thing

The question I hear most from new business owners is some version of the same thing: "Julio, I already have my LLC, so I'm structured correctly, right?"

The honest answer is: it depends on what you mean by that.

Registering an entity is a good first step to protect your personal assets from the risks of the business. But the entity by itself doesn't decide how much you pay in taxes. That's decided by another layer, one a lot of owners never set up, or set up without understanding what they're choosing.

Choosing your structure well does three things: it protects your assets, it organizes how the business runs, and it optimizes your taxes. In this article I'll walk through the entity types, the key difference between legal structure and tax structure, and how to evaluate the decision that moves the most money: the S-Corp election.

The most common business structures in the U.S.

There are five main structures an owner can choose from, based on their legal, tax, and management needs.

Sole Proprietorship. The simplest and cheapest way to start. You and the business are the same legal entity. Upside: no formal state registration, easy and low-cost to run, fine for starting out as a freelancer or side hustle (with whatever professional licenses your industry and state require). Downside: unlimited liability. Your personal assets are exposed to the business's debts or lawsuits.

Limited Liability Company (LLC). One of the most popular structures, because it combines liability protection with tax flexibility. Upside: it separates your personal assets from the business, it lets you choose how you're taxed (as a sole proprietorship, S-Corp, or C-Corp), and it's simpler to maintain than a corporation. Downside: state registration and annual fees, and you have to keep clean books so you don't "pierce the corporate veil." If you pay personal expenses from the business account or keep no records, you can lose the liability protection. That's why a solid operating agreement matters.

C-Corporation. A fully separate entity from its owners. Not common for independent owners, but it fits businesses with aggressive expansion plans or that want investors. Upside: full separation of assets, access to investors through issuing shares, and benefits like health or retirement plans for employees. Downside: double taxation (the company pays at the corporate level, around 21% federal plus state, and dividends are taxed again at the personal level), plus more paperwork and cost.

Nonprofit Organization. Created for charitable, educational, religious, or community purposes, not to distribute profits. If it meets IRS requirements it can get 501(c)(3) status, which exempts it from federal tax and makes the donations it receives deductible.

And the S-Corporation, which isn't a business type. The S-Corp shows up in every structure conversation, but technically it isn't an entity type, it's a tax election. It's important enough that I cover it separately below, because it's exactly where the most expensive confusion lives.

The distinction almost no one makes: legal structure isn't tax structure

When you register an LLC with the state, you create a legal entity. Your business exists as something separate from you: it has asset protection, it can sign contracts, it can have employees. That's the legal structure.

What that entity doesn't do is tell the IRS how to tax you.

And that's the most common confusion: people think registering an LLC settles the tax question. It doesn't. The legal structure handles the existence and protection of the business. The tax structure is a completely separate layer, and that difference matters more than it seems once the numbers start to grow.

If you didn't make a tax election, the IRS made one for you

If you formed an LLC and never made a formal election, the IRS applies a default classification, and it isn't necessarily the one you want.

• If you're the only owner, the IRS classifies you as a sole proprietorship. The profit flows straight to your personal return, and on it you pay not just income tax but also self-employment tax: 15.3% of every dollar of net profit.
• If there are several partners, it classifies you as a partnership. Same mechanism: each partner is taxed on their share of the profit, including self-employment tax on their piece.

Neither default is the most efficient as the business grows. They're simply what the IRS applies when you don't make a decision.

The S-Corp doesn't change your business, it changes how the IRS taxes you

"Switching to an S-Corp" doesn't mean creating a new company or changing your legal entity. What it does mean is changing your LLC's tax classification with the IRS, through Form 2553. Your LLC stays the same entity, with the same protection and the same contracts. What changes is how your taxes are calculated.

The S-Corp doesn't lower your income tax and doesn't eliminate employment taxes. What it does is introduce a split the default LLC doesn't have: it lets you divide the business income into two parts.

• One part goes out as a W-2 salary, which pays payroll taxes (the employer-and-employee equivalent of self-employment tax).
• The other part goes out as a profit distribution, which doesn't pay that tax.

That's the benefit. Nothing more, nothing less. And it only exists if there's a real gap between a reasonable salary and the business's profit.

The example in numbers: the difference can be about $6,786 a year

Picture a business with $250,000 in annual revenue and $150,000 in operating expenses. Net profit before taxes is $100,000.

Scenario 1: LLC taxed as a sole proprietorship. The full $100,000 flows to the personal return. Self-employment tax is figured on 92.35% of that profit (a built-in adjustment), so on about $92,350 you pay 15.3%, which comes to roughly $14,100, plus whatever income tax applies.

Scenario 2: the same business, taxed as an S-Corp. The owner assigns a reasonable salary of $48,000. Payroll taxes are figured on that salary: about $7,344. The remaining $52,000 is paid out as a distribution, and that distribution doesn't pay self-employment tax.

Difference: about $6,786 a year. (Illustrative example; your real number depends on your profit, your reasonable salary, your tax rate, and the cost of running the S-Corp.)

That money doesn't come from earning more or doing anything questionable. It comes from understanding how the rules work and making an informed decision. These are the rules the tax code itself sets, available to anyone who applies them with judgment.

When is it worth evaluating the S-Corp?

The IRS never set a specific number, but there's a clear financial logic. The S-Corp isn't free. Between payroll, more structured bookkeeping, and extra filings, maintaining it costs roughly $1,500 to $3,000 a year, depending on your state and accountant. The right question is: do the self-employment tax savings beat that cost?

As a practical reference, once net profit clears about $40,000 to $50,000 a year, the conversation starts to make sense. Below that range, the saving usually doesn't justify the cost of running the structure. Above it, it's worth running the analysis, and that analysis uses your real numbers, not generic percentages from the internet.

The three operational changes that come with an S-Corp

When you elect S-Corp, the IRS sees you as both owner and employee. That brings three consequences you take on from day one:

1. You have to pay yourself a W-2 salary. If you work actively in your business, the IRS requires a reasonable salary for your services. It isn't optional. Paying yourself a token salary is exactly what the IRS audits.
2. You have to run payroll. Even if you're the only person: withholdings, quarterly forms (Form 941), and an annual W-2. It takes a system.
3. The bookkeeping gets formal. A balance sheet, tracking distributions, and a more complex return than a simple LLC's. Accounting costs go up.

The tax saving comes bundled with operational order. If the business is informal today, the problem isn't a tax problem.

Reasonable salary: where the saving is won or lost

This is where I see the most mistakes, and where the IRS pays the most attention.

A reasonable salary isn't "the lowest possible to maximize the distribution." It's what you'd pay someone with your experience, in your industry, doing exactly your job. The law doesn't set a fixed percentage: there's no "30/70" or "40/60" rule floating around social media. There's the reasonableness standard, and the IRS can challenge any salary that looks artificially low.

If the IRS finds the salary unreasonably low, it can reclassify the distributions as salary and collect the payroll taxes owed, plus interest and penalties. That's where the "saving" turns into the problem you were trying to avoid. (If you want to go deeper on setting your pay, I cover it in how to pay yourself as an owner.)

When NOT to make the switch

Just as important as knowing when it's worth it is knowing when it isn't:

• If the business doesn't generate real, consistent profit. If revenue swings a lot or almost everything covers expenses and your own pay, there's nothing to optimize.
• If there's no meaningful gap between the reasonable salary and the profit. If what you should pay yourself is nearly the whole profit, the distribution is tiny and the saving is close to zero.
• If you're not willing to operate with more order. Payroll, reports, formal bookkeeping. Without that discipline, the switch adds friction without the benefit.

And it definitely isn't worth it if the decision comes from something you saw online. The S-Corp isn't a badge that says you've made it. It's a tax-efficiency tool that only works at the right time.

How to choose your structure

Before deciding, weigh four factors:

• Risk level: if you handle large volumes of transactions or clients, an LLC or corporation protects you better against lawsuits.
• Business size: if you're an independent professional just starting, a sole proprietorship may be enough at first.
• Future plans: to expand or attract investors, a corporation is usually the better fit.
• Tax efficiency: once there's consistent profit, the tax election (starting with evaluating the S-Corp) is what moves the needle most.

Something people often miss: you don't choose your structure once and forget it. What makes sense at $80,000 of profit may not at $250,000. Your structure should evolve with your business, and the conversation with your accounting team should be periodic, not just at filing time.

Frequently asked questions

Can I have an LLC and elect to be taxed as an S-Corp?

Yes. The LLC is the legal structure; the S-Corp is a tax election made with the IRS through Form 2553. They're two separate layers that coexist: your entity is still the same LLC.

What's the difference between an LLC and an S-Corp?

An LLC is a legal entity registered with your state. An S-Corp is a federal tax classification. They're not competing options on the same level: an LLC can be taxed as a sole proprietorship, an S-Corp, or a C-Corp. The real comparison is between tax classifications, not "LLC or S-Corp."

When is it worth evaluating the S-Corp election?

As a general rule, it starts to make sense around $40,000 to $50,000 or more of annual net profit. Below that, the cost of running an S-Corp usually outweighs the tax saving. But this is a planning heuristic, not an IRS rule: the real answer depends on your reasonable salary, payroll and bookkeeping costs, state taxes, and retirement goals.

What is a reasonable salary and why does it matter?

It's what you'd pay someone with your experience, in your industry, for your work. It's the foundation of an S-Corp that holds up: if it's artificially low, the IRS can reclassify your distributions as salary and collect back taxes with penalties.

What happens if I never made a tax election?

The IRS applies the default: sole proprietorship for single-member LLCs, partnership for multi-member LLCs. You can change it going forward, but not retroactively.

Can I reverse the S-Corp election later?

Yes, but with restrictions. If you revoke the election, you generally can't elect it again for 5 years without IRS approval.