Your Side Business Doesn't Need an S-Corp Yet

Most people hear "S-corp" and think it's a discount code for self-employment tax. File the election, split your income into salary and distributions, keep 15.3% off part of it. Done.

That's true. It's also not the whole math.

An S-corp doesn't just change your tax return. It changes what your business has to do every year to stay one: run payroll, file a separate business return, and in some states pay a franchise tax whether you made money or not. None of that shows up in the "how much will I save" conversation. For a business owner running a side consulting practice or a small rental-arbitrage operation, it's often the difference between the election helping and the election quietly costing money.

What the S-corp actually changes

Self-employment tax is 15.3% on your net profit as a sole proprietor or single-member LLC: Social Security and Medicare, both halves, because there's no employer splitting it with you.

An S-corp lets you split that profit into two buckets: a salary, which is subject to that 15.3%, and a distribution, which isn't. Pay yourself a "reasonable" salary (the IRS's term, meaning market rate for the work, not whatever number saves you the most) and everything above that comes out as a distribution, untouched by SE tax.

That's the entire mechanism. It's not a loophole. It's also not free.

What it costs to keep running

Once you elect S-corp status, you're required to run actual payroll, even if you're the only employee. That means a payroll service, quarterly filings, and W-2s at year-end, call it $600 to $1,000 a year for a solo owner on something like Gusto.

Then there's the return itself. An S-corp files its own return (Form 1120-S) separate from your personal return, which usually means a second preparation fee layered on top of what you were already paying, often $1,000 to $3,000 or more depending on your state, your preparer, and how clean your books are.

Some states add a third cost regardless of the first two. California charges a minimum $800 franchise tax whether the business turns a profit or not. New York City doesn't recognize S-corp status at all and taxes you as if you'd never elected it.

Add it up and a solo owner is looking at roughly $1,600 to $4,000 a year, sometimes more, just to maintain the structure, before it's saved a single dollar in SE tax.

Where the math actually turns

Here's the number that matters: the SE tax savings have to clear the maintenance cost before the S-corp is worth anything.

Picture a consultant running $45,000 a year in net profit from a side practice, on top of a W-2 job. Uncapped, that $45,000 is fully exposed to 15.3% SE tax: about $6,900. Split it through an S-corp with, say, a $30,000 reasonable salary and $15,000 in distributions, and the SE tax exposure drops to roughly $4,600, a savings of around $2,300.

Against $1,600 to $4,000 in payroll and filing costs, that $2,300 in savings is thin. At the cheap end of that range, it's a small win, maybe a few hundred dollars ahead. At the pricier end, which is common once you add a state franchise tax or a more thorough preparer, it's a net loss: you spent more running the structure than it saved you.

Now run the same consultant at $90,000 in net profit. A $50,000 reasonable salary against $40,000 in distributions drops SE tax exposure from roughly $13,800 down to about $7,650, a savings near $6,100. Against that same $1,600 to $4,000 maintenance cost, this clears with real room to spare, even on the expensive end.

The CPA firms that publish this math don't agree on an exact line, but they cluster in the same range: the S-corp starts reliably paying for itself somewhere between $60,000 and $80,000 in consistent net profit. That range moves depending on your state and preparer, so treat it as a starting point, not a rule. Below it, you're often funding the accountant's Q4 instead of your own.

The actual decision framework

Three questions before you file:

Is the income consistent, or is this year an outlier? A single good year doesn't justify a structure you're stuck maintaining through the next three average ones.

Does the state you're in help or hurt? A franchise tax minimum or a state that ignores S-corp status entirely moves your breakeven number up, sometimes by a lot.

Can you actually run payroll without it becoming a second job? The SE tax savings are real, but they assume you (or someone you're paying) is handling quarterly filings correctly. Get the reasonable salary wrong or miss a filing, and the "savings" turn into penalties.

If you're clearing $80,000+ in consistent net profit from the activity, the S-corp conversation is worth having. Below $50,000, the honest answer is usually: not yet.

What's the actual net profit this side activity has produced, consistently, for the last two years? Not the best year. The average one.