Do you owe self-employment (SE) tax on non-wage income that you collect only occasionally or in a one-off circumstance? Some sources of income may not be subject to the dreaded SE tax. Here’s what you should know if you earn income from “irregular” sources.

What Is SE Tax?
SE tax is the way the U.S. Treasury Department collects Social Security and Medicare taxes on non-wage income from business-related activities. For 2019, the SE tax rate is 15.3% on the first $132,900 of net SE income. The rate has two components:

• 2.9% for the Medicare tax, and
• 12.4% for the Social Security tax.

Above the $132,900 threshold, the Social Security tax component goes away, but the 2.9% Medicare tax continues before rising to 3.8% at higher income levels. There’s no limit on the Medicare tax component.

Individuals who are regularly self-employed must include SE tax with their quarterly estimated federal income tax payments to avoid an interest charge penalty.

Important: The Social Security Administration recently announced that in 2020 the 15.3% maximum SE rate will apply to the first $137,700 of net SE income. That ceiling is up by 3.6% compared to 2019. Meanwhile, Social Security benefit payments will go up by only 1.6% next year.

Will You Owe It on Random Income?

SE tax applies only to individuals who engage in a trade or business. So, if you’re not regularly self-employed and you earn income from some random work, occurrence or one-off circumstance, you don’t owe SE tax — even if the income would be subject to SE tax if you were regularly self-employed in that activity.

You don’t owe SE tax unless the net income in question is from a trade or business. In the landmark Groetzinger case, the U.S. Supreme Court ruled that an activity must be conducted with “continuity and regularity” and with a “profit motive” to incur SE tax. Therefore, income earned from an isolated or sporadic activity isn’t generally subject to SE tax because the random activity doesn’t rise to the level of a trade or business.

The U.S. Tax Court reaffirmed this treatment in its 2016 Ryther decision. Here, the former owner of a steel company had income from sales of scrap metal that he had stockpiled over the years before his steel company was dissolved. The court opined that the income was excluded from net SE income. The scrap metal was neither inventory nor primarily held for sale to customers in the ordinary course of a trade or business. The taxpayer’s sales occurred only once or twice per month and only once per day. Therefore, the sales were too sporadic to constitute a trade or business, and the income wasn’t subject to SE tax.

Hypothetical Examples

Here are five examples to show how the trade or business standard might be applied.

1. Jim the self-employed construction supervisor. Jim regularly works for a few construction companies. He agrees to supervise the construction of a neighbor’s new home in his “spare time” and collects $30,000 for his efforts.

This is the first time Jim has done this kind of sideline work. The IRS might argue that it’s so closely related to his regular self-employed work that he owes SE tax on the $30,000. However, Jim could reasonably take the position that he does not owe SE tax on income from a one-off activity. This is a situation that would require input from a tax professional.

2. Tim the construction company employee. Tim is employed full-time by a construction company as a construction supervisor. Similar to the previous scenario, he agrees to supervise the construction of a neighbor’s new home in his “spare time” and collects $30,000 for his efforts.

This is the first time Tim has done this kind of sideline work. The IRS might argue that he owes SE tax on the $30,000 because the sideline work is so closely related to his regular job. In other words, the IRS might claim that Tim is in the business of being a construction supervisor — as an employee or otherwise.

But Tim has never before done such work on a self-employed basis. So, he could reasonably take the position that he does not owe SE tax on income from a one-off activity. This is another situation that would require input from a tax pro.

3. Abby the former active realtor.For years, Abby was an active realtor, but she took time off to be a stay-at-home mom. She has maintained her realtor license “just in case.” In 2019, she earns a $30,000 fee for referring an acquaintance to another realtor who sells the acquaintance’s home for a significant commission.

It’s clear that Abby isn’t currently in the realtor business. So, it’s highly unlikely that the IRS could successfully argue that she owes SE tax on the $30,000 referral fee.

4. Gabby the former part-time realtor.A few years ago, Gabby dabbled as a part-time realtor, but she lost interest. Even so, she maintained her realtor license “just in case.” In 2019, she earns a $30,000 fee for referring an acquaintance to another realtor who sells the acquaintance’s home for a significant commission.

It’s clear that Gabby isn’t currently in the realtor business. So, it’s highly unlikely that the IRS could successfully argue that she owes SE tax on the $30,000 referral fee.

Even if Gabby gets lucky several years in row, earning a referral fee now and again, it seems reasonable to take the position that she doesn’t owe SE tax on random referral fees that she collects just by answering the phone and making an occasional call to another realtor. This sporadic activity doesn’t constitute a trade or business, because Gabby doesn’t do it with continuity and regularity. But it’s another situation that should be discussed with a tax pro.

Important: If you take the position that irregular income is SE-tax-exempt because it’s not from a trade or business, you relinquish the right to claim deductions for any related expenses. For example, neither Abby nor Gabby would be able to write off their annual realtor license fees or the costs of continuing education classes to keep their licenses in force.

5. Jake the teenage entrepreneur.This summer, 16-year-old Jake mowed lawns, painted fences and took care of pools for some neighbors. He earned $3,000 from these activities. He doesn’t owe SE tax on this income. Why? As a full-time high school student, Jake’s not in the yard care and outdoor home maintenance business, even if he does such work several summers in a row.

Bottom Line

Random income is often SE-tax-exempt — and there are categories of non-random income that are also SE-tax-exempt, such as billboard rental income where your only real “work” is cashing checks. If you have questions or want more information on this issue, check with your tax advisor.

Realty Check: Random Income Isn’t Tax-Free

Irregular income might be free from self-employment (SE) tax, because it’s not from a trade or business. But it’s not federal-income-tax-free. Under the tax law, it’s treated as miscellaneous income, which is fully taxable. State income tax may also be due.