What is the IRS $400 self-employment rule?

If your net self-employment profit is $400 or more, you must file Schedule SE and pay self-employment tax (15.3%). Below $400, no SE tax is owed.

Does the $400 threshold apply to gross or net income?

Net income — gross self-employment income minus deductible business expenses. Legitimate deductions can reduce your net profit below $400 and eliminate SE tax.

📅 Last reviewed: June 2026 🏷️ Side Hustle Taxes 📖 ~2,100 words

The IRS $400 Self-Employment Rule: When Your Side Income Becomes Taxable (2026 Guide)

Q: Do I owe SE tax if a client paid me in cash and sent no 1099?

Yes. The $400 rule applies to all net self-employment profit regardless of whether a form was issued. Cash and peer-to-peer payments are still taxable and reported on Schedule C.

Q: Is the Additional Medicare Tax part of SE tax?

The 0.9% Additional Medicare Tax applies to combined wages and SE income above $200,000 (single) or $250,000 (married). It is calculated on Form 8959, not on Schedule SE.

Q: If my net profit is exactly $400, do I owe SE tax?

The threshold is $400 or more, so $400 triggers the filing and SE tax requirement. The computed SE tax at exactly $400 is small but Schedule SE must still be filed.

You earned a few hundred dollars selling crafts online, doing odd jobs, or freelancing on weekends. Do you owe the IRS anything? The answer hinges on a simple threshold: $400 in net self-employment profit. Here's what that means, what taxes apply, and how to use deductions to stay below it — or handle it properly when you cross it.

The $400 Rule Explained

Under IRS rules, if your net self-employment income is $400 or more, you are required to file a federal tax return and pay self-employment (SE) tax. This is codified in IRS Publication 334 and IRC Section 1401.

The Rule: Net self-employment profit ≥ $400 → Must file Schedule SE + pay SE tax.
Net self-employment profit < $400 → No SE tax owed (but income may still be taxable).

This rule applies even if you have a regular W-2 job. Your side hustle income is evaluated independently for SE tax purposes — your W-2 wages do not offset SE tax liability on the side gig.

Gross vs. Net: The Critical Distinction

The $400 threshold applies to net profit, not gross income. Net profit = gross business income minus deductible business expenses.

Example A: You earned $700 freelancing but had $400 in business expenses.
Net profit = $700 − $400 = $300 → Below $400 → No SE tax

Example B: You earned $700 with only $200 in expenses.
Net profit = $700 − $200 = $500 → At or above $400 → SE tax owed

This means tracking your business expenses is crucial. Every legitimate deduction that brings your net profit below $400 eliminates your SE tax obligation entirely.

What Taxes Apply When You Cross $400?

Two separate taxes apply to self-employment net profit:

1. Self-Employment (SE) Tax — 15.3%

This covers Social Security (12.4%) and Medicare (2.9%). It's calculated on 92.35% of net profit (because employees only pay on the employee share, so the IRS gives self-employed workers a 7.65% reduction).

Net profit: $2,000
SE taxable base: $2,000 × 92.35% = $1,847
SE tax: $1,847 × 15.3% = $282.59

2. Federal Income Tax (Bracket-Based)

Your net self-employment profit is added to your other income and taxed at your marginal federal rate. You get two deductions first:

Deduct ½ of SE tax (above-the-line deduction)
Deduct the standard deduction or itemized deductions

For many people with modest side income, these deductions bring taxable income to zero or very low, meaning little to no federal income tax is owed even when SE tax applies.

State Income Tax

Most states also tax self-employment income. If you live in a no-income-tax state (TX, FL, WA, TN, NV, WY, SD, AK), you won't owe state tax. Otherwise, add your state's rate on top.

Real Examples

Example 1 — Etsy Seller

Sarah sells handmade candles on Etsy. Her 2026 numbers:

Gross sales: $3,200
Supplies and materials: $1,400
Etsy fees and shipping: $380
Net profit: $3,200 − $1,780 = $1,420

SE tax base: $1,420 × 92.35% = $1,311
SE tax: $1,311 × 15.3% = $200.58
Half SE deduction: −$100.29
Standard deduction (single): −$16,100
She also has $42,000 W-2 income. Total taxable income reduced.
SE tax bill: ~$201 (plus federal income tax on the $1,420 profit at marginal rate)

Example 2 — Weekend Handyman

Mike does small home repairs on weekends. Gross: $1,800. His only expense is $50 in supplies.

Net profit: $1,800 − $50 = $1,750
SE tax: $1,750 × 92.35% × 15.3% = $247.30

Mike could reduce his SE tax by tracking more expenses: vehicle mileage to job sites, additional tools, business phone usage, professional apps. Use our Deduction Calculator to find missed deductions.

Example 3 — Under the Threshold

Lisa does occasional tutoring. Gross: $650. Her business expenses (teaching materials, commuting mileage): $280.

Net profit: $650 − $280 = $370 → Below $400 → No SE tax owed
The $370 is still potentially reportable as "other income" if her total income requires a return, but she owes zero SE tax.

Edge Cases and Special Rules

Church Employee Income

If you're a church employee (paid by a church or church-controlled organization), the SE threshold is just $108.28 — much lower than the $400 rule.

Combined Sources

If you have multiple side gigs, combine all net self-employment profits. You can't offset a profit from one business with a loss from another for SE tax purposes — actually you can if both are Schedule C activities. Consult a CPA for businesses with mixed losses.

Filing Requirement vs. SE Tax

Even below $400 net, you may still be required to file a federal return if your total gross income exceeds the standard deduction. The $400 rule is only for the SE tax filing trigger, not the general income tax filing requirement.

Hobby vs. Business

The IRS distinguishes between a business (profit motive) and a hobby (no profit motive). Hobby income is taxable but hobby expenses are not deductible under current law (post-TCJA). If you repeatedly show losses, the IRS may reclassify your business as a hobby. Consult a CPA if you have recurring losses.

How to Use Deductions to Manage Your Tax Liability

The most effective way to reduce SE tax is to reduce net profit through legitimate deductions:

Mileage: Every business mile at 67¢ reduces profit
Home office: $5/sq ft simplified method (up to 300 sq ft = $1,500)
Equipment & supplies: Computers, tools, materials used for business
Software subscriptions: Design tools, invoicing apps, accounting software
Professional development: Courses, books, conferences
Business phone/internet: Prorated for business use percentage

Use our Deduction Comparison Tab to calculate which combination of deductions reduces your taxable profit the most.

Do You Need to Pay Quarterly Estimated Taxes?

If you expect to owe $1,000 or more in federal taxes for the year, the IRS generally requires quarterly estimated payments. For modest side income with annual SE tax under $1,000, you may be able to wait until the April filing deadline — but check your specific situation.

Use our Quarterly Tax Calculator to determine your quarterly payment schedule and avoid underpayment penalties.

Deep Dive: Why the $400 Threshold Exists and How "Net Earnings" Is Computed

The $400 figure is not arbitrary. Under IRC Section 1401, SE tax applies to your net earnings from self-employment. The IRS rounds the tax computation in a way that produces zero liability below $400 of net profit, so $400 became the de facto filing trigger. The technical definition of net earnings is your Schedule C net profit (Line 31), with a few adjustments (generally limited to the deductible portion of SE tax and certain statutory employees).

Two points trip up first-time filers:

Your W-2 job does not shield the side gig. SE tax is computed only on self-employment income. A $75,000 salary does not "use up" or offset the SE tax on a $900 side-gig profit — you simply pay both the payroll tax on wages and the SE tax on the gig.
The Social Security portion can cap out. The 12.4% Social Security slice of SE tax only applies up to the annual wage base ($176,100 for 2025; indexed annually). If your W-2 + SE combined income already exceeds that base, only the 2.9% Medicare portion (and the 0.9% Additional Medicare Tax above $200,000 single / $250,000 married) applies to the side gig.

Household employees take note: If you are a church employee, the SE trigger drops to $108.28 of church wages. Everyone else uses the $400 line. The lower figure reflects the special treatment of ministerial and church-controlled organization compensation under IRC Section 1402.

Worked Example 4 — A Combined Gig Portfolio Just Over the Line

Priya runs three small gigs in 2026. Because the $400 test looks at combined net SE profit, we add them all up:

Etsy crafts: gross $3,200, expenses $1,780 → net $1,420
Rover dog-sitting: gross $900, expenses $80 → net $820
Fiverr design: gross $1,500, expenses $400 → net $1,100
Total net SE profit: $3,340

SE tax base (92.35% rule) = $3,340 × 0.9235 = $3,084.49
SE tax (15.3%) = $3,084.49 × 0.153 = $471.93
Half-SE above-the-line deduction = $235.97
Federal income tax on the $3,340 profit depends on her bracket (say 12%): ~$401, reduced by the $236 SE deduction → roughly $165 more income tax.
Total federal tax on the side gigs ≈ $637.

If Priya had skipped tracking the $2,260 of expenses across her three gigs, her net profit would be $4,600 and her SE tax alone would be about $650 — so good recordkeeping saves her roughly $180 in SE tax, plus the income-tax benefit of those deductions.

Worked Example 5 — W-2 Employee With a Small Side Gig

David earns a $75,000 salary and makes $900 net from weekend photography. The salary already covers the Social Security wage base's lower portion, but Medicare still applies to the side gig:

Net side-gig profit: $900
SE tax base: $900 × 0.9235 = $831.15
SE tax (15.3%) = $127.17
Half-SE deduction: −$63.59
Because his W-2 already exceeds the Social Security wage base, the full $127 is essentially the Medicare slice — but the math is identical using the 15.3% formula.
Total SE tax on the side gig ≈ $127.

David might assume his employer "already withholds enough," but the side income is separate. He should either increase his W-4 withholding or make a small quarterly payment so he does not owe a penalty at filing. See our Underpayment Penalty guide.

Common Mistakes Around the $400 Rule

Ignoring a 1099-NEC. Platforms must file a 1099-NEC once you earn $600+. The IRS gets a copy. Not filing because the amount "seems small" invites a matching notice.
Failing to deduct expenses to drop below $400. Many people with $350–$500 gross never record costs, pushing them over the line unnecessarily.
Treating everything as a hobby. Reporting hobby income but deducting expenses is not allowed post-TCJA. If you have a real profit motive, file as a business and take your deductions.
Forgetting state side-income tax. Even if federal SE tax is modest, your state may tax the net profit.
Assuming one W-2 "covers" the gig. As shown above, SE tax is computed independently on self-employment income.
Missing the church-employee $108.28 threshold. Ministers and certain church workers owe SE tax at a much lower level.

⚠️ The $600 1099-K / 1099-NEC threshold is separate from the $400 SE rule. You can owe SE tax even if no form was issued (e.g., you earned $450 from cash clients). Conversely, receiving a 1099 does not by itself mean you owe SE tax — only your net profit above $400 does.

Step-by-Step: Determine Whether You Owe SE Tax

Step 1 — Total every dollar of self-employment gross income

Add 1099-NEC, 1099-K, 1099-MISC (non-employee comp), and even cash/check payments clients did not report. Side income is taxable whether or not you got a form.

Step 2 — Subtract every legitimate business expense

Mileage, supplies, software, home office, phone, equipment. Document each with a receipt or log. The result is net profit.

Step 3 — Apply the $400 test

If net profit is $400 or more, you must file Schedule SE. If below $400, no SE tax — but check your overall filing requirement.

Step 4 — Compute SE tax on 92.35% of net profit

Multiply net profit by 0.9235, then by 15.3% (or use our Base SE Tax Calculator).

Step 5 — Decide how to pay

If total federal tax owed will exceed $1,000, set up quarterly payments or raise W-4 withholding to avoid an underpayment penalty.

Cross-References: The $400 Rule in Context

The threshold is the gateway to several related topics on this site:

Base SE Tax Calculator — See exactly how 15.3% and the 92.35% factor are applied: Base SE Tax Calculator.
Mileage Deduction — Often the single biggest expense that pushes side-gig profit under $400: Mileage Deduction Guide.
Home Office Deduction — The $5/sq ft simplified method (max $1,500) can wipe out a small profit: Home Office Guide.
Quarterly Estimated Taxes — Once you cross $400 and owe $1,000+, you need a payment plan: Quarterly Calculator.
Underpayment Penalty — What happens if you skip those payments: Penalty Guide.

FAQ

I made $380 net. Do I need to file a return?

You don't owe SE tax on $380. Whether you need to file depends on your total income for the year. If your combined gross income is below the standard deduction ($16,100 single in 2026), you generally don't need to file.

Does the $400 rule apply to each side gig separately?

If you have multiple self-employment businesses, you combine net profits from all Schedule C activities. The $400 threshold applies to your total net SE profit.

What form do I use to pay SE tax?

Schedule SE (Form 1040). The calculated SE tax then flows to your Form 1040 total tax liability.

Do I owe SE tax if a client paid me in cash and sent no 1099?

Yes. The $400 rule applies to all net self-employment profit, regardless of whether a form was issued. Cash and peer-to-peer payments are still taxable income, and you report them on Schedule C.

Can a business loss offset my W-2 income?

A Schedule C net loss can offset other income, including W-2 wages, reducing your overall taxable income. However, repeated losses may draw IRS hobby-activity scrutiny under IRC Section 183, so keep records showing a profit motive.

Is the Additional Medicare Tax part of SE tax?

Yes. The 0.9% Additional Medicare Tax applies to combined wages and SE income above $200,000 (single) or $250,000 (married filing jointly). It is calculated on Form 8959 and reported with your return, not on Schedule SE itself.

If my net profit is exactly $400, do I owe SE tax?

The threshold is "$400 or more," so $400 triggers the filing and SE tax requirement. In practice the computed SE tax at exactly $400 is small (about $56), but you must still file Schedule SE.

References

IRS Publication 334 — Tax Guide for Small Business
Schedule SE Instructions — irs.gov
IRS Publication 535 — Business Expenses

The figures and rules above summarize the 2026 IRS guidance. The primary sources below carry the full legal language and worksheets; confirm against the current-year forms before filing, and treat any calculator result as an estimate, not formal tax advice.