Illinois Tax Tables
Illinois Tax Tables provide a complete reference of how state income tax is calculated for each supported year. These tables summarise the official rules issued by the Illinois Department of Revenue and present them in a clear structure that matches the calculations used in our Illinois Tax Calculator. They are useful for checking withholdings, estimating liability, reviewing historical tax years and understanding how state policy shapes taxable income.
Quick Access Tools
Tax Years
Select a tax year to view the official Illinois tax rates and rules used in our calculators. Each page shows the brackets or flat tax rate, deduction amounts, credit structures, withholding guidance and any year-specific updates published by the Illinois Department of Revenue. You can also access the matching Illinois Tax Calculator for precise calculations for that year.
How Illinois Calculates Income Tax
Illinois uses a flat income tax rate applied to all taxable income. These rules determine how wages and other taxable income are assessed for Illinois returns, with updated tables released each year to reflect legislation and inflation changes. For a broader explanation of how tax tables work, see our Tax Tables guide.
Certain jurisdictions within Illinois also levy local or county income taxes. These appear in the annual state tax tables and may affect residents, part-year residents or nonresidents depending on local rules.
Illinois supports resident, nonresident and part-year filing rules. The tax tables help clarify which thresholds apply when income is earned both inside and outside the state.
What Is Contained in the Illinois Tax Tables?
Each tax-year page provides a structured summary of the components Illinois uses to calculate individual income tax. While details vary by year, the state tax tables generally include the following elements:
- Flat tax rate applied to taxable income.
- Standard deduction amounts for each filing status.
- Itemized deductions where permitted under Illinois law.
- Dependent and family-related credits including any child-based or filer-based reductions.
- State Earned Income Credit (EIC), including percentage match and income limits.
- Retirement income rules including partial or full exemptions for pensions or Social Security.
- State withholding tables used by employers for payroll calculations.
Together, these elements provide a transparent breakdown of how Illinois calculates tax for each year. This structure helps taxpayers review year-to-year changes, employers validate payroll withholding and financial planners analyse how Illinois’s rules differ from federal requirements. All values shown in our Illinois Tax Tables match the official figures published by the state.
Frequently Asked Questions
Do I need to file IL-1040-X if the IRS changes my income?
Yes. If the IRS adjusts your federal return and it affects Illinois tax, you must file IL-1040-X within 120 days of receiving the federal notice.
Are donations made through Schedule G-L tax-deductible?
Yes. Your Schedule G-L donations are eligible for a federal charitable deduction if you itemize on your federal Form 1040 Schedule A. Keep a copy of the filed schedule and any Lottery confirmation of your gift. The contribution will increase your Illinois payment or reduce your refund, but may lower your federal taxable income in the following year.
Changing jobs mid-year in IL
Update income/withholding and frequency; brackets are flat but credits/exemptions still matter.
Who must file Schedule FD?
You must file Schedule FD if you are a former Illinois resident who receives income (such as installment sale gains or deferred bonuses) sourced from Illinois that became taxable for federal purposes during 2026.
What documentation must accompany Schedule 1299-DA?
Attach copies of the other states’ filed tax returns, W-2s, or K-1s showing withholding and payments. Failure to attach proof can lead to denial of the credit. For convenience, you can track and upload copies directly through the MyTax Illinois portal.
Important Notes
All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.