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
529 plan deduction (Bright Start/Bright Directions)?
Illinois allows a state deduction for contributions to its 529 plans (limits apply).
Can I amend to claim missed credits or deductions?
Yes. You may file IL-1040-X to add credits such as the Illinois Credits (Schedule ICR) or education expense credit you forgot to claim originally.
How can I verify that my donation reached the fund I chose?
After the filing season, each state agency receiving contributions issues a public report confirming the total received from taxpayers. You can also contact the Illinois Department of Revenue or the administering agency for that specific fund for confirmation. Keep a copy of your return and any receipt from your tax preparer or e-file provider showing your donation entry.
I paid tax to another state—can I avoid double taxation?
Yes. File Schedule CR to claim a credit for income tax paid to another U.S. state on the same income while an IL resident.
Why is Schedule 1299-C important for transparency?
It maintains fairness within Illinois’s incentive programs. By recapturing credits when eligibility changes, the state ensures that incentives reward long-term economic activity rather than short-term gains. For taxpayers, it preserves credibility and helps avoid legal disputes with the Department of Revenue.
Important Notes
All calculations are estimates for guidance only. Always review your return and consider professional advice when submitting official filings.