Illinois Side Hustle Tax Calculator
Calculate your Illinois state tax (4.95%), federal tax, and self-employment tax on 1099 income.
Last updated: January 2026 · Data from IRS Rev Proc 2024-40
Illinois side hustlers benefit from a flat state income tax, but at 4.95%, it's higher than neighboring Indiana's 3.0%. The Land of Lincoln taxes all income earned by residents, and Chicago-area freelancers should be aware that while there's no city income tax, the overall cost of living and sales taxes can impact your bottom line. Over 1.3 million Illinois residents earn freelance or gig income.
How Side Hustle Taxes Work in Illinois
Illinois uses a flat tax system:
**Illinois state tax:** - Flat rate: 4.95% on all net income - No brackets or progressive rates - Applies to self-employment income after deductions
**Good news for Illinois side hustlers:** - No local income taxes anywhere in Illinois - Chicago doesn't add city income tax - Simpler tax calculation than progressive states
Note: Illinois doesn't tax retirement income, but this doesn't affect current side hustle earnings.
What Illinois Side Hustlers Owe
Let's say you're a single filer in Chicago with a $55,000 W-2 job and $14,000 in side hustle income from freelance photography, with $2,000 in expenses.
**Your estimated taxes on the side hustle:** - Net self-employment income: $12,000 - Federal SE tax (15.3% of 92.35%): ~$1,697 - Federal income tax on side income: ~$2,640 (22% bracket) - Illinois state tax (4.95%): ~$594 - **Total additional tax: ~$4,931**
Your effective rate on the side hustle is about 41%. The flat rate makes Illinois more predictable than states like California or New York.
Illinois Tax Deadlines 2025
Illinois estimated tax deadlines match federal: - **Q1**: April 15, 2025 - **Q2**: June 15, 2025 - **Q3**: September 15, 2025 - **Q4**: January 15, 2026
Use Form IL-1040-ES for Illinois estimated tax payments. No separate local payments needed since Illinois has no local income taxes.
Common Deductions for Illinois Freelancers
Illinois freelancers benefit from the state's conformity to federal adjusted gross income—most federal deductions automatically reduce your Illinois taxes. **Home office deduction**: Claim dedicated business space using the simplified method ($5/sq ft, max 300 sq ft) or actual expenses for larger deductions. **Vehicle mileage**: 67 cents/mile for 2025 covers gas, maintenance, and depreciation; essential for rideshare drivers and mobile service providers. **Equipment and software**: Computers, phones, cameras, and business software are deductible; Section 179 allows immediate expensing. **Professional development**: Courses, certifications, conferences, and educational materials that improve your business skills qualify. **Health insurance premiums**: Self-employed individuals can deduct 100% of health, dental, and long-term care insurance premiums. **Retirement contributions**: SEP-IRAs (up to 25% of net self-employment income) and Solo 401(k)s reduce both federal and Illinois taxable income. **Marketing expenses**: Website costs, business cards, advertising, and promotional materials are fully deductible. Illinois's flat tax means every deduction saves you 4.95% in state taxes plus your federal marginal rate.
Illinois Side Hustle Tax FAQ
What is Illinois's tax rate on side hustle income?
Illinois has a flat 4.95% income tax rate on all taxable income, including self-employment earnings. This applies regardless of how much you earn.
Does Chicago have an income tax on side hustles?
No, Chicago and all other Illinois cities do not have local income taxes. You only pay the state 4.95% flat rate plus federal taxes on your side hustle income.
How do I report side hustle income in Illinois?
Report your side hustle income on your federal Schedule C, then transfer the net profit to your Illinois IL-1040. Illinois uses your federal AGI as the starting point for state taxes.
Do I need to register my side hustle in Illinois?
Sole proprietors using their legal name don't need to register, but if you use a business name (DBA), you must file an Assumed Business Name with your county clerk. LLCs and corporations must register with the Illinois Secretary of State. If you sell products, you'll need a Retailer's Occupation Tax license.
When are Illinois quarterly tax payments due?
Illinois follows federal quarterly deadlines: April 15, June 15, September 15, and January 15. Use Form IL-1040-ES. You must make estimated payments if you expect to owe $500 or more in Illinois taxes.
Can I deduct SEP-IRA contributions on my Illinois taxes?
Yes, SEP-IRA and Solo 401(k) contributions reduce your federal AGI, which Illinois uses as its starting point. This means retirement contributions reduce both federal and Illinois taxes—saving you at your federal rate plus 4.95% on every dollar contributed.
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