Illinois state income tax on your paycheck
Illinois applies a flat 4.95% income tax. Here is how it appears on your pay stub.
How Illinois state tax works in 2025
Illinois uses a flat 4.95% rate on most wage income, applied after any state-level standard deduction or allowances.
Flat 4.95% state income tax. Chicago has additional payroll-related rules.
Illinois official sources
Official sources
- IRS Publication 15-T, Federal Income Tax Withholding Methods — IRS · 2025 · last verified 2025-04-01
- IRS Topic 751 — Social Security and Medicare Withholding Rates — IRS · 2025 · last verified 2025-04-01
- SSA — Contribution and Benefit Base — SSA · 2025 · last verified 2025-04-01
- U.S. DOL — Overtime Pay (FLSA) — DOL · last verified 2025-04-01
More Illinois guides
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