Why Do Some Side Hustlers Get Audited Over Hobby Versus Business Classification?

By The Penny Plan Editorial Team Published July 13, 2026 6 min read

A side hustle has shown a loss on the tax return three years running, and now a letter has arrived asking for more documentation. It can feel sudden, but this particular scrutiny follows a fairly well-established pattern in how the tax system treats activities that resemble hobbies.

The quick answer

Tax authorities distinguish between a business, which is operated with the intent to make a profit, and a hobby, which is pursued mainly for personal enjoyment. Businesses can generally deduct ordinary expenses and, in many cases, use losses to offset other income; hobby-related expenses generally cannot offset other income in the same way. Filers who repeatedly claim losses on an activity that looks more like a hobby draw closer attention because the classification directly affects how much tax is owed.

What tends to trigger a closer look

Factors generally weighed in the classification

Tax guidance typically lists a set of factors used to evaluate whether an activity is a business or a hobby, none of which is decisive on its own.

Effort and expertise

Whether the person operates the activity in a businesslike manner, keeps accurate records, and has or is developing relevant expertise all factor into the analysis.

History of income and losses

A pattern of occasional profitable years mixed with losses reads differently than an unbroken string of losses, particularly if losses are attributable to circumstances outside normal operations, like a slow first year or an unusual one-time expense.

Dependence on the income

Whether the person depends on income from the activity for their livelihood is one factor considered, alongside whether personal pleasure or recreation is a significant motivating element.

How this connects to other side income questions

Classification questions like this often overlap with related tax topics, such as whether commuting miles to start a gig shift count the same as miles driven during it, because both involve documenting an activity carefully enough to support the deductions being claimed. Similarly, someone weighing whether a side hustle nets more than working overtime is implicitly grappling with the same profit-motive question that shows up in a hobby-versus-business review, just from a planning angle rather than an audit angle.

What to weigh if this comes up

The takeaway

Hobby-versus-business scrutiny generally follows a pattern of sustained losses combined with limited businesslike operation, rather than any single deduction. Understanding the factors involved, and keeping the recordkeeping to match, is the most direct way to prepare for the possibility that a side activity gets a closer look. Keeping records this organized also makes it easier to know how long to keep tax records in case a return from an earlier year ever gets a second look.