Side-Hustle Taxes: What 1099 Workers Need to Know

The first time a freelancer or gig worker sits down to file taxes, the number often comes as a shock. Income tax is the part everyone expects — self-employment tax is the part that catches people off guard, because nothing was ever withheld from a 1099 payment the way it would have been from a paycheque. Understanding what’s actually owed, and what can be deducted against it, is the difference between a manageable bill and a scramble every April.

The self-employment tax shock

When you’re a W-2 employee, your employer withholds Social Security and Medicare tax from every paycheque and matches half of it themselves. When you’re self-employed, there’s no employer to split that cost — you owe both halves yourself, through self-employment tax.

Self-employment tax runs at roughly 15.3%, applied to 92.35% of your net self-employment earnings (the 92.35% adjustment exists because the calculation accounts for the fact that an employee’s employer-paid half of payroll tax was never treated as income in the first place). This is durable — the mechanics have held steady for a long time, even though other tax figures move year to year.

Crucially, this is on top of regular income tax, not instead of it. A freelancer earning a healthy net profit can find themselves paying self-employment tax and income tax on the same earnings, which is why a side hustle’s effective tax rate often surprises people who only budgeted for income tax.

You owe tax even without a 1099

A common and costly misconception: “I never got a 1099, so I don’t have to report it.” That’s false. Your obligation to report and pay tax on self-employment income exists regardless of whether you receive a 1099 form. The 1099 is an information return the payer files to tell the IRS what they paid you — it doesn’t create your tax liability, and its absence doesn’t erase it.

This matters more than ever because the reporting thresholds that determine when platforms and clients are required to issue a 1099 have shifted repeatedly in recent years, and are likely to keep shifting — check current rules for the specific platform or payer you’re dealing with. But regardless of where that threshold sits in a given year, the underlying rule doesn’t change: if you earned it, you owe tax on it, form or no form.

Schedule C basics

Self-employment income and expenses are reported on Schedule C, attached to your regular Form 1040. The shape is simple: total revenue from the activity, minus your deductible business expenses, equals net profit — and that net profit is the number that flows into both income tax and self-employment tax calculations.

Multiple side hustles generally each get their own Schedule C if they’re meaningfully different activities, though small or related activities can sometimes be combined. If you’re running more than one side income stream, it’s worth checking with a tax professional on how to structure the filings correctly rather than lumping everything together by default.

Legitimate deductions

Every dollar of legitimate business expense reduces the net profit that both income tax and self-employment tax are calculated on — so tracking deductions properly has an outsized effect on the total bill. Common ones for side hustlers:

• Mileage for business driving, at the current IRS standard mileage rate (this rate changes yearly, so check the current figure rather than using last year’s) — or actual vehicle expenses if that method works out better for your situation.
• Supplies used directly for the business — materials, tools, packaging, anything consumed in delivering the work.
• Software and subscriptions used for the business — invoicing tools, design software, a paid app subscription used to run the hustle.
• A percentage of your phone bill, proportional to business use, if you use a personal phone for both business and personal calls.
• A home office, if you have a space used exclusively and regularly for the business — see home office deduction rules for the exclusive-use test and how to choose between the simplified and actual-expense methods.

Keep the deductions genuinely tied to the business. The line between a legitimate business expense and a personal expense you’re hoping to write off is exactly where audits tend to focus.

Half of self-employment tax is itself deductible

One piece of relief: half of the self-employment tax you pay is deductible against your income tax, taken as an above-the-line adjustment rather than an itemised deduction. This exists because that half roughly mirrors the employer-paid portion a traditional employee’s company would have covered — the tax code effectively lets you deduct the “employer’s share” even though you’re paying both sides yourself. It doesn’t reduce the self-employment tax itself, but it does lower the income tax calculated afterward. This mechanic is durable and doesn’t depend on year-to-year rate changes.

Quarterly estimated payments

Because nothing is withheld from 1099 income the way it is from a paycheque, the IRS expects self-employed people to pay tax as they earn it, four times a year, rather than in one lump sum at filing time. Skipping this can mean an underpayment penalty on top of the tax itself. See estimated quarterly taxes for who’s required to pay, the safe-harbor rules that keep you penalty-free, and a full worked calculation from a Schedule C profit.

Record-keeping habits that actually help

The single best habit for side-hustle taxes is separating the money before it ever mixes with personal finances:

• A separate bank account for the side hustle, even a free one, so business income and expenses aren’t tangled up with groceries and rent in your statement.
• Receipts kept as you go — a folder, an app, a scanned copy the day of purchase — rather than reconstructed from memory in April.
• A simple running log of income and expenses updated monthly, not left until filing season.

None of this needs to be elaborate. A basic spreadsheet updated consistently beats a sophisticated system abandoned after the first month.

Retirement options for the self-employed

Self-employment income also opens retirement accounts that don’t exist for W-2-only workers — a SEP IRA and a solo 401(k) both let self-employed people contribute meaningfully more than a standard IRA allows, sheltering a chunk of side-hustle profit from current-year tax. Contribution limits and rules vary by account type and change over time, so they’re worth researching specifically once the hustle is generating consistent profit, rather than assuming a standard IRA is the only option available.

When the hustle is a hobby

Not every side activity rises to the level of a business for tax purposes. The IRS distinguishes a genuine business — run with the intent to profit, with reasonable records and businesslike behavior — from a hobby, an activity pursued mainly for enjoyment that happens to bring in some money. Hobby income is still taxable, but hobby losses generally can’t be used to offset other income the way a real business’s losses can. If your side hustle isn’t yet profitable, the hobby-vs-business distinction is worth understanding before you assume you can deduct your way to a loss that lowers your overall tax bill.

This is general information, not tax advice — self-employment tax mechanics are durable, but mileage rates, platform reporting thresholds, and retirement contribution limits all change over time, so confirm current figures with the IRS or a tax professional before filing.