FreelanceIllinois quarterly tax calculator for freelancers.
Illinois taxes income at a flat 4.95%, starting from your federal adjusted gross income, less an exemption allowance of $2,925 per person for 2026. There are no brackets, so the only question is how much to send and when.
Your next estimated payments
$15,034
Federal, due Jan 15, 2027
$3,213
Illinois, due Jan 15, 2027
Each is what you still owe for the year, split across the deadlines still ahead.
Next federal payment $15,034, due Jan 15, 2027. Next Illinois payment $3,213, due Jan 15, 2027.
Federal safe harbor $11,800 per payment
Pay at least $11,800 across the year, a quarter of it by each deadline, and the IRS underpayment penalty cannot apply. Based on 100% of last year's federal tax, which is the lower of the two tests.
Some 2026 deadlines have already passed. A quarter of that total was due by each one, so a quarter paid late can still carry a penalty; paying now stops it growing. See what it costs.
Illinois safe harbor $2,892 per payment
Pay at least $2,892 across the year, on the Illinois installment dates, and the Illinois underpayment charge cannot apply. Based on 90% of this year's estimated Illinois tax. Add last year's Illinois tax below to see if that test is cheaper.
Your taxable income is past the qualified business income threshold, so that federal deduction is being reduced by the wage limit. If you are in a specified service field, the reduction can be steeper than shown.
| What you earned | |
|---|---|
| Expected 1099 income | $85,000 |
| Less deductible business expenses | $12,000 |
| Net profit from freelancing | $73,000 |
| Self employment tax | |
| Earnings subject to self employment tax | $67,416 |
| Social Security portion | $8,360 |
| Medicare portion | $1,955 |
| Additional Medicare over the threshold | $0 |
| Self employment tax | $10,315 |
| Federal income tax | |
| Deductible half of self employment tax | $5,157 |
| Qualified business income deduction | $10,349 |
| Standard deduction for your filing status | $16,100 |
| Other W-2 income added back | $0 |
| Taxable income after deductions | $41,394 |
| Federal income tax | $4,719 |
| Federal total for 2026 | $15,034 |
| Less federal estimated payments already made | $0 |
| Still owed to the IRS | $15,034 |
| Your next federal payment | $15,034 |
| Illinois income tax | |
| Federal adjusted gross income, where Illinois starts | $67,843 |
| Less Illinois exemption allowance | $2,925 |
| Illinois taxable income | $64,918 |
| Tax at the flat 4.95% rate | $3,213 |
| Credits and surtaxes (none modeled) | $0 |
| Illinois total for 2026 | $3,213 |
| Less Illinois estimated payments already made | $0 |
| Still owed to Illinois | $3,213 |
| Your next Illinois payment | $3,213 |
| Federal and Illinois tax for 2026 | $18,247 |
Stop re-entering this every quarter. FreelanceCFO tracks it from your real income and warns you before each deadline.
Start freeHow Illinois is different.
Illinois taxes income at a flat 4.95%. These are its 2026 estimated payment dates. If one falls on a weekend or holiday, it moves to the next business day.
2026 payment dates
- Apr 15, 2026
- Jun 15, 2026
- Sep 15, 2026
- Jan 15, 2027
What changes in Illinois
- The exemption allowance is $2,925 per person for 2026, and it is zero once federal AGI passes $250,000 ($500,000 joint).
- Estimated payments are only required if you expect to owe more than $1,000 of Illinois tax after withholding and credits.
- Safe harbor is 90% of this year's tax or 100% of last year's, with no 110% step up for high earners.
- Four equal payments on April 15, June 15, September 15, 2026, and January 15, 2027.
Questions answered.
What is the Illinois income tax rate for 2026?
A flat 4.95% of your net income, which is Illinois base income (for most freelancers, federal adjusted gross income) less the exemption allowance. The allowance is $2,925 per person for tax years beginning January 1, 2026.
Do I have to make Illinois estimated tax payments?
Yes, if you expect your 2026 Illinois tax to be more than $1,000 after subtracting withholding and credits. A single filer with no withholding reaches that at roughly $23,000 of Illinois base income.
What is the Illinois safe harbor for estimated tax?
If you pay at least 90% of this year's tax or 100% of last year's tax in four equal, timely installments, you may not be subject to the late payment penalty. Unlike the federal rule, the prior year test does not rise to 110% for high earners.