Engaged in a Trade or Business: The IRS Test That Decides Your Tax Bill in 2026

You sold $8,000 of handmade ceramics on Etsy last year, drove for a rideshare app on weekends, and rented out your camper a few times through a peer-to-peer site. Are you running a business, juggling three hobbies, or some combination of both? The IRS has an opinion — and that opinion controls whether you can deduct your expenses, owe self-employment tax, or face a surprise penalty for guessing wrong.

The phrase "engaged in a trade or business" sounds like dry tax jargon. In practice, it's the single most important classification for anyone earning income outside a traditional W-2 paycheck. It separates Schedule C filers (who get to deduct ordinary and necessary expenses) from hobbyists (who, after recent law changes, can deduct almost nothing). It determines whether foreign-owned companies owe U.S. tax, whether a real estate investor qualifies for favorable treatment, and whether your side hustle's losses can offset your day-job income.

This guide unpacks the IRS definition, the nine-factor test the agency uses, the 2026 changes under the One Big Beautiful Bill Act (OBBBA), and the practical steps you can take to land on the right side of the line.

What "Trade or Business" Actually Means

The Internal Revenue Code uses the phrase "trade or business" hundreds of times, but it never defines it. Courts and the IRS have filled in the gap over decades, settling on a workable test built on three pillars:

1. A profit motive. You must enter and continue the activity primarily to earn income or profit, not for personal enjoyment, social standing, or recreation.
2. Continuity and regularity. Sporadic, occasional, or one-off activity doesn't qualify. The activity needs to look like an ongoing enterprise.
3. Active involvement. You (or agents working on your behalf) must be substantively engaged. Passive holding of investments generally is not a trade or business — though there are exceptions, particularly for real estate professionals and securities traders.

The Supreme Court reinforced this framework in Commissioner v. Groetzinger (1987), holding that a full-time gambler who placed bets daily for a living was engaged in a trade or business. The Court emphasized two things: the activity was pursued in good faith for profit, and it was carried on with continuity and regularity. Casual gamblers fail both prongs.

For most readers, the practical question is narrower: when does the IRS consider your side income a business rather than a hobby? That's where Section 183 — the "hobby loss" rule — and its nine-factor test come in.

The Nine-Factor Hobby Loss Test

Treasury regulations under Section 183 list nine factors the IRS weighs when deciding whether your activity has the requisite profit motive. No single factor wins. The agency looks at the full picture, and so do tax courts when the issue is litigated.

1. The manner in which you carry on the activity. Do you keep books and records? Do you have a separate business bank account, written business plan, marketing materials, and a system for evaluating profitability? Operating in a businesslike way is the strongest single signal.
2. Your expertise (or your advisors'). Did you study the field, take courses, consult experts, or hire a coach? Plunging in without preparation suggests recreation; methodical expertise suggests business intent.
3. Time and effort spent. Substantial personal time, especially time taken away from another job, points toward a business. Working evenings and weekends only — when the activity is pleasurable — points toward a hobby.
4. Expectation that assets will appreciate. Even if current income is low, an expectation that the underlying assets (land, equipment, inventory, intellectual property) will gain value can satisfy the profit-motive test. This factor often saves real estate, breeding, and farming activities.
5. Success in similar activities. A track record of building and selling other businesses signals you know how to operate for profit. A first-timer doesn't lose automatically, but the track record is helpful.
6. History of income or losses. Repeated losses, especially during what should be the start-up phase, hurt. The IRS understands that new ventures lose money for two or three years; persistent losses well beyond that period attract scrutiny.
7. The amount of occasional profits. Even a single year with a substantial profit can demonstrate that the activity is capable of producing income. Tiny profits sandwiched between large losses are less convincing.
8. Your financial status. If the activity's losses generate a tax benefit you wouldn't have otherwise (because you have substantial income from other sources), the IRS gets suspicious. High earners deducting horse-breeding losses are classic audit bait.
9. Personal pleasure or recreation. If the activity is inherently fun — racing cars, breeding dogs, photographing landscapes — the IRS gives extra weight to the other factors. Enjoying your work doesn't disqualify a business, but it raises the bar.

There's also a presumption that helps taxpayers: if your activity shows a profit in three of any five consecutive years (two of seven for horse-related activities), the IRS presumes you have a profit motive. The burden then shifts to the agency to prove otherwise.

What Changed in 2026: The OBBBA Hobby Income Rule

The One Big Beautiful Bill Act, signed in 2025, took effect for the 2026 tax year and made one change that hits hobbyists particularly hard.

Before 2018, hobby expenses could be deducted as miscellaneous itemized deductions, capped at hobby income. The Tax Cuts and Jobs Act suspended those deductions through 2025. The OBBBA made the suspension permanent and added a new wrinkle: hobby income must be reported in full, but no expenses are deductible against it for federal income tax purposes.

The result: if you earn $5,000 from a hobby and spend $4,500 to produce that income, you pay tax on the full $5,000. A real business with the same numbers would pay tax on $500. The classification question has never mattered more.

A few specific points to keep in mind for the 2026 filing year:

• Reporting location. Hobby income still gets reported on Schedule 1, Line 8 ("Other income"), not Schedule C.
• No self-employment tax. Hobby income isn't subject to the 15.3% self-employment tax. That's the silver lining for taxpayers stuck on the wrong side of the line.
• State treatment varies. Some states still allow hobby expense deductions even though federal law doesn't. Check your state's rules separately.
• Casual sales are different. Selling personal items at a loss (cleaning out the garage on Facebook Marketplace) generally isn't taxable at all and isn't hobby income. The 1099-K thresholds dropped in recent years, though, so you may receive a form even when no tax is owed.

A Practical Decision Framework

Here's how to think through your own situation before tax season.

Step 1: Honestly Assess Your Intent

If you started the activity because you love it and money is a bonus, you're starting on the hobby side of the line. If you started it because you saw a market opportunity and built a plan to capture it, you're starting on the business side. Both can change over time, but be honest about where you are now.

Step 2: Look at Your Records

Pull up whatever you have for the activity right now. Can you produce a profit-and-loss statement? A spreadsheet of revenue and expenses? A business bank account statement? If the answer is "I have a shoebox of receipts and some PayPal screenshots," you have a documentation problem that hurts you on Factor 1 regardless of your intent.

Step 3: Check Your Profit History

Have you turned a profit in three of the last five years? If yes, you're inside the safe harbor. If no, look at why. Were the losses driven by genuine investment in growth, or by ongoing operating expenses with no path to profitability?

Step 4: Compare Yourself to a Real Business in the Same Field

If you ran into another person doing the same activity at scale, what would their setup look like? Separate entity, business insurance, written contracts, marketing budget, dedicated workspace? The closer your operation looks to that picture, the stronger your case.

Step 5: Document Your Conclusion

Whatever you decide, write it down. A short memo to yourself — "I treat this activity as a trade or business because [reasons], and here's the documentation that supports that position" — costs you nothing now and is invaluable if a future auditor asks how you reached your conclusion.

Common Trap: The "Engaged in U.S. Trade or Business" Question for Foreign Businesses

If you're a non-U.S. company or individual selling into the United States, "engaged in a U.S. trade or business" (often abbreviated ETOB or USTB) is a separate, parallel question that determines whether your U.S.-source income is taxed on a net basis under the regular rules or on a gross basis at the 30% withholding rate.

The factors here are slightly different and emphasize:

• Dependent agents in the U.S. Employees or contractors in the U.S. who work substantially for you and have authority to bind the business or perform substantive (not just clerical) functions.
• A fixed place of business. A leased office, warehouse, or store front in the U.S. is a strong indicator.
• Considerable, continuous, and regular activity. Isolated transactions don't qualify; an ongoing pattern does.

A foreign company that ships goods into the U.S. from abroad, with no U.S.-based agents or facilities, is generally not engaged in a U.S. trade or business — even if its U.S. customers spend millions. Add a U.S. employee who actively negotiates contracts, and the analysis flips. Tax treaties layer additional rules on top, often substituting "permanent establishment" for ETOB.

If you're operating cross-border, the stakes are large enough to justify a tax attorney rather than a flowchart.

Real-World Examples

A few illustrative scenarios:

• The Etsy seller. You started selling knitwear three years ago. You have a separate Etsy seller account, track every roll of yarn, file Schedule C, and reinvest profits in a better camera and inventory. Profits in two of three years. Strong business position.
• The eBay garage cleaner. You sold $2,000 of old electronics and clothes last year, all at a loss compared to original purchase price, with no plans to keep going once the basement is empty. Not a business, not a hobby — generally not taxable, though you may receive a 1099-K to report and reconcile.
• The weekend race-car driver. You spend $40,000 a year on car prep and travel, win $3,000 in occasional prize money, love every minute, and your day job is a high-paying engineering role. Classic hobby-loss territory. Even if you call yourself a business, the OBBBA rules now mean you pay tax on the full $3,000 with no offset.
• The freelance developer. You quit your job, registered an LLC, set up a separate bank account, took on three retainer clients, and built a website. First year showed a small loss after equipment purchases. Solid business position even with the loss; the start-up phase is recognized.
• The aspiring real estate investor. You bought one rental property this year. The activity is an investment, not a trade or business — until you accumulate enough properties and management activity to qualify as a "real estate professional" under separate rules. The label has major implications for whether passive loss rules limit your deductions.

Why Bookkeeping Is the Foundation

Look at the nine-factor test again. Notice how many factors hinge on records: businesslike manner of operation, profit history, response to changes in operations, the time you actually invest. You can't demonstrate any of these without clean books.

The taxpayers who lose hobby-loss cases overwhelmingly fail on documentation. They have intent and effort and even genuine profit potential, but they can't produce a contemporaneous record of how they ran the activity. The auditor concludes — reasonably — that no businesslike person would operate without records, so this can't be a real business.

Setting up a separate ledger from day one solves this problem. Every transaction tagged, every expense categorized, every quarterly review documented. When the IRS asks, you hand over a clean general ledger and a story that matches it.

Keep Your Trade-or-Business Status Defensible

Whether you're running a side hustle, scaling a freelance practice, or weighing the hobby-vs-business question for the first time, the IRS classification follows from the records you keep. Beancount.io provides plain-text accounting that gives you a transparent, version-controlled audit trail you can reproduce years later — exactly the kind of evidence the nine-factor test rewards. Get started for free and build the documentation foundation that turns a contested classification into an obvious one.