Illinois State Tax Guide (2026)
Single flat rate 4.95% on all taxable income. Reciprocity with IA, KY, MI, WI.
Why it matters: State income tax is only part of the picture. Residency, sourcing of income, credits, and local taxes change the effective burden. Use the state income tax estimator for a number, and check reciprocity and convenience-rule status before a move or remote-work arrangement.
This guide summarizes structural facts for planning. It is not a substitute for the official Illinois tax code or a licensed preparer.
Not tax, legal, or financial advice
FiscTalk provides general educational information from public sources. Tax outcomes depend on your full facts, filing history, and jurisdiction-specific rules that change yearly. Before filing or making decisions, consult a licensed CPA, EA, or attorney. FiscTalk is not a fiduciary and is not affiliated with the IRS or any state agency.
Sources & methodology
Figures as of: 2026-08-09