TL;DR: An LLC and an S-corp can run the same business, but they keep different books. A default LLC is pass-through simplicity — Schedule C, self-employment tax on all profit, no payroll. An S-corp election adds payroll: a reasonable salary through a real payroll system, distributions on top, and separate records for both. The trade is lower self-employment tax for more bookkeeping, and the math usually starts working somewhere around $40–80k of net profit. Here's what actually changes month to month.
There are a hundred articles explaining what an LLC is. This isn't one of them. If you're a founder choosing between staying a default LLC and electing S-corp status, you don't need a civics lesson — you need to know what changes in the work you do every month and what shows up on your tax bill.
So let's skip the definitions and talk about the part you'll actually feel: your books.
The default LLC: simple by design
A single-member LLC is, by default, a disregarded entity. The IRS basically ignores it for income tax and treats the business as you. That has clean consequences for bookkeeping:
- Profit flows to Schedule C on your personal return. Revenue minus expenses equals net profit, and that number is your taxable business income.
- You pay self-employment tax on all of it — roughly 15.3% covering Social Security and Medicare, on top of ordinary income tax.
- There's no payroll. When you pay yourself, you take an owner's draw — you move money from the business to your personal account. A draw isn't an expense and it isn't taxed as a separate event; you're already taxed on the profit whether you draw it or not.
The bookkeeping here is genuinely light. You categorize income and expenses, track your draws as equity (not as a business expense), and you're done. One set of books, one tax form, no filings between you and the IRS beyond your annual return and your quarterly estimated payments.
The cost is that self-employment tax applies to every dollar of profit. Make $120k in profit and you're paying SE tax on the whole thing. That's the leak the S-corp election is designed to plug.
The S-corp election: same business, new payroll department
An S-corp isn't a different kind of company — it's a tax election you can make on top of an LLC (or a corporation). Make it, and the IRS changes one big thing: how the owner gets paid. Now you must split your pay into two buckets:
- A reasonable salary, run through actual payroll. This is wages — subject to payroll taxes, withholding, W-2 reporting, and the whole apparatus.
- Distributions, which are the remaining profit you take out. Distributions are not subject to self-employment/payroll tax.
That second bucket is the entire point. You only pay payroll tax on the salary portion, not on the distributions. If a reasonable salary for your role is $70k and the business profits $130k, you've shielded the $60k of distributions from the ~15.3% SE tax. That's real money.
But — and this is what the explainers gloss over — you've just hired yourself a payroll department.
What the S-corp actually adds to your monthly books
The election turns a light bookkeeping job into a moderate one. Now your books have to track, every month:
- Payroll runs. You (or a payroll provider) issue yourself a paycheck on a schedule, withhold taxes, and remit them. That generates payroll entries, tax liabilities, and reconciliations that simply didn't exist before.
- Owner compensation as a distinct line. Salary is wage expense. It can't be blurred with distributions or draws. Your books need a clean, separate owner-comp category.
- Distributions tracked separately. Distributions reduce equity and must be recorded as such — not as salary, not as an expense. Mixing these up is one of the most common S-corp bookkeeping errors, and it's exactly the kind of thing that creates problems if the salary-vs-distribution ratio ever gets questioned.
- Payroll tax liabilities. The withheld and employer-side taxes sit as liabilities until remitted. Your books carry balances they didn't carry as a plain LLC.
- More filings. Quarterly and annual payroll filings, plus a separate business tax return (Form 1120-S) and K-1s — versus the LLC's single Schedule C.
None of this is exotic. But it's the difference between "categorize transactions once a week" and "run payroll, reconcile it, and keep three flavors of owner money straight." If your books are already messy, the S-corp election makes the mess more expensive.
When the math actually starts to work
Here's the honest threshold. The S-corp saves you self-employment tax on distributions, but it costs you: payroll software or a provider, a more involved tax return, possibly a higher bookkeeping or CPA bill, and your own time keeping it clean. Sometimes a state filing fee or franchise tax on top.
Very roughly, those costs start to be outweighed by the SE-tax savings somewhere in the $40,000–$80,000 net-profit range. Below it, you're often spending as much on payroll and admin as you save. Above it, the savings can be several thousand dollars a year and climbing.
That range is wide on purpose, because the real answer depends on:
- A reasonable salary for your role. The IRS expects your salary to be defensible for the work you do. A low salary with huge distributions invites scrutiny. The higher your reasonable salary, the smaller the distribution bucket you can shield.
- Your state. Some states tax S-corps directly or charge franchise fees that eat into the federal savings.
- What payroll and tax prep cost you in dollars and hours.
This is a "run the numbers with a CPA" decision, not a blog-post decision. But knowing which numbers matter — net profit, a reasonable salary, your real admin cost — lets you have a sharp conversation instead of a vague one.
What this means for the books you keep
Whichever path you're on, the through-line is the same: the tax structure only works if the bookkeeping behind it is clean and current.
- As a default LLC, you need accurate net profit and clean separation of draws from expenses — mostly so your estimated taxes and Schedule C are right.
- As an S-corp, you need all of that plus a disciplined split between salary, distributions, and payroll liabilities — every month, not reconstructed in March.
That's where keeping books current beats keeping them perfect-once-a-year. Prosper auto-categorizes ~80–90% of transactions from the merchant, amount patterns, and your prior categorizations, and surfaces only the exceptions for review — so owner comp, distributions, and payroll-related entries stay correctly tagged as they happen instead of getting untangled at filing. When you do elect S-corp, the salary-vs-distribution line stays accurate all year, which is exactly what you want if anyone ever asks how you arrived at it.
The structure decision is a CPA conversation. The bookkeeping decision is a daily-habit one — and the second is what makes the first actually pay off.
FAQ
What's the actual bookkeeping difference between an LLC and an S-corp?
A default LLC is pass-through: profit flows to Schedule C and you pay self-employment tax on all of it, with no payroll to run. An S-corp election forces you onto payroll — you pay yourself a reasonable salary (with withholding, filings, and separate payroll records) and take the rest as distributions. The S-corp adds real monthly bookkeeping: payroll runs, owner-comp tracking, and a clean split between salary and distributions.
At what profit does an S-corp make sense?
Very roughly, the self-employment tax savings start to outweigh the added payroll and admin costs somewhere around $40,000–$80,000 of net profit, depending on your state, a reasonable salary for your role, and what payroll and tax prep cost you. Below that range the savings often don't cover the overhead. Run the numbers with a CPA before electing.
Does an S-corp election make bookkeeping harder?
Yes, modestly. You add payroll (or a payroll provider) and need to track owner compensation, payroll tax liabilities, and distributions as distinct categories — not lump them into "owner pay." It's manageable, especially if your books stay current. Tools like Prosper keep categorization clean so the salary-vs-distribution split stays accurate all year instead of getting untangled at tax time.
Not professional tax or accounting advice. Consult a CPA for your situation.