Second Income Tax Basics for Side Hustlers
What to set aside, what to track, and what most people get wrong
By the Monthly Income Booster editorial team · Updated · How we research and fact-check
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Side income arrives without tax withheld, which is why the first year catches people out. The fix is simple bookkeeping from day one rather than reconstruction in April.
Set Money Aside as It Arrives
Move a fixed percentage of every payment into a separate account the day it lands. Guessing at year end is how people end up owing more than they have.
Track Deductible Costs
Mileage, supplies, platform fees, software and a portion of home costs are commonly deductible for self-employed work. Untracked expenses are simply money given away.
Payment Platforms Report
Marketplace and payment platforms issue forms to both you and the tax authority. Income you didn't record is still visible.
Quarterly Payments
Once side income is substantial, estimated quarterly payments may be required to avoid penalties. The quarterly tax calculator here gives a working estimate.
Get Advice at Scale
A one-off session with an accountant usually pays for itself the first year your side income gets serious. This page is general information, not tax advice.
Official sources
Tax rules, limits and pay data change. Check the current figures with the primary source before acting on them.
Frequently Asked Questions
How much should I set aside for taxes?+
Many self-employed people reserve a fixed share of each payment. Your rate depends on total income and state — use the self-employment tax calculator here for an estimate.
Do I have to report small side income?+
Income is generally reportable regardless of whether a form is issued. Keeping a log makes it straightforward.
What can I deduct?+
Ordinary and necessary business costs — mileage, supplies, fees, software. Rules vary, so confirm specifics with a tax professional.
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