Hobby or business?
Check every box that's true for your side income. The IRS weighs these same factors when it decides how your activity should be reported.
This mirrors the factors the IRS actually uses (Topic 419) but isn't a determination — the agency looks at your full facts and circumstances, and no single factor decides it alone. Hobby income is reported as Other Income on Schedule 1, line 8j, with no expense deductions. Business income is reported on Schedule C, with deductions allowed, but is subject to 15.3% self-employment tax once net earnings clear $400.