Should You Use an S Corporation for a Sideline or Part-time Business?

Pretty regularly, people come to us for help with an S corporation they’ve already set up. And that’s fine.

We love helping small businesses. And we love S corporations. No, seriously.

But one unfortunate situation we commonly encounter is where someone with a regular, full-time job sets up an S corporation for a side-line, part-time business.

Usually, setting up an S corporation for a sideline or part-time business doesn’t work.

This post talks about why you usually don’t want to set up an S corporation for a sideline or part-time business if you’ve got a regular, full-time job.

And then, because the subject matter is so similar, this post also talks about the idea of using an S corporation for a very small, part-time venture. Usually S corporations make little to no sense for these ventures, too.

S Corporations Cost More Money

To start your thinking, you need to know that an S corporation increases your accounting and tax preparation costs.

Without getting into all the nitty-gritty details, you probably want to think about the decision as a $2,500 annual expense at a minimum. And you might end up paying closer to $4,000. But let me break this down.

For starters, you’ll pay probably $1,500 to $2,000 a year to a tax accountant to prepare the annual 1120S corporation tax return.

In most states, you will pay another $500 to $1000 a year in payroll taxes that you’ll owe even in the case where the only person working in the business is the shareholder.

Finally, an S corporation will require you to do a bunch of additional fiddling with payroll processing: quarterly returns, annual wage statements, regular paychecks and tax deposits. You will probably want to pay a service to “do” this payroll processing. That choice adds another $500 to $1,000 to the costs.

And now you’re at $2,500 to $4,000 in annual costs just to have an S corporation.

You Generally Must Pay Some Wages

Here’s the next thing to keep in mind: In order to make your S corporation tax return look reasonable, you’re going to have to pay some substantial chunk of the business profit out to yourself as wages.

The average one-owner S corporation pays its shareholder-employee about $40,000, by the way. So I think most S corporation owners probably want to get close to that number or have a good reason for not being there.

Now what’s weird about this is that in your real job, the full-time one you spend more of your time at, you may already earn a solid wage. But that wage won’t matter.

The comparison you’ll want to make (and it’s the same one I’ll guess the IRS computers likely make) is how your shareholder-employee wages compare to the leftover profits you distribute to the shareholders.

I think, for example, that even if you in your regular job earn $200,000 a year, you need to pay the first big chunk of your sideline or part-time business profit as wages.

And another thing—and probably more relevant to the typical small, sideline S corporation: If you make only a modest amount of profit in the venture (keeping in line with the sideline nature of the whole enterprise), I think you probably need to pay out most of the profit as wages.

For example, if you have a part-time business that makes, say, $10,000 or $20,000 a year, logically to me, most of that profit would likely stem from your labor and so should probably be treated as wages.

The bottom line here, then: While what you want to do with an S corporation is shield profits from employment taxes? You’ll find that hard to do with a sideline operation.

Tip: You can use our free S Corporation Tax Savings Calculator to estimate S corporation tax savings for your specific situation.

Marginal Employment Tax Rate Matters

Something else you want to know.

In the case where someone already earning the FICA limit operates a sideline business? Yes, that side business profit if earned in an unincorporated business is subject to self-employment taxes of roughly 2.9% to 3.8%.

But if that person instead operates a sideline business as an S corporation? The employment taxes run roughly 10% to 12% on the first chunk of the profits the S corporation labels as wages. And this means, in effect, you’re often going backwards at first, in terms of payroll tax savings, with a sideline or part-time S corporation.

This weirdness occurs because the FICA, Medicare, FUTA and equivalent state payroll tax limits get reset or partially reset to zero for the new employer.

Two Examples Illustrate the Problem

Let me give you a couple of examples so you understand what I mean.

The limits for Federal unemployment tax (FUTA) and state employment tax (SUTA) reset for the new corporation. Accordingly, even if you’ve fully satisfied your unemployment tax obligations in your first, primary job, you may end up paying these taxes again for the next job. FUTA, by the way, can run 6% on the first $7,000 of wages. And SUTA varies by state, but can easily run $1000 or more for an employee.

And here’s another example: While an individual who’s already broken through the FICA limit on one job ($168,600 in 2024) doesn’t need to pay 6.2% Social Security taxes on the wages from a second job, the employer providing the second job does.

The bottom line here? You will find it more difficult than you would expect to minimize payroll taxes using a S corporation when you’re talking about a sideline business.

And more to the point: In many cases, you can’t justify the $2,500 to $4,000 of out-of-pocket costs or the hassle factor of using an S corporation for a sideline business.

What about Part-time Businesses?

Let me throw out one related comment here, too.

Now, again, please understand: We love S corporations. They often work great. Someday, if you have a successful full-time small business, you’ll probably want to operate that venture as an S corporation. Absolutely.

However, all the stuff that causes problems with the S corporation choice for a sideline business probably also causes problems for a part-time business.

You have this relatively high cost you pay just to “play the game.” Again, maybe $2,500 to $4,000 a year.

Furthermore, you probably have to first pay the “reasonable wages” component out of the profit, which means your business needs to be making something quite a bit in excess of that “reasonable wages” amount in order to even break even on the costs.

An Alternative to the S Corporation Option

Can I make one related suggestion?

If you want to limit your liability, you may want to use a limited liability company instead of an S corporation. We’ve got do-it-yourself LLC formation kits which most people can use to quickly set up an LLC themselves. And note that an LLC can be easily converted to an S corporation at the start of any tax year. Here’s the list of links:

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