State Residency Rules → Illinois

Illinois Tax Residency Rules: Domicile, Not Day Counts

The rule in one paragraph

Domicile controls; no bright-line day test.

The details

Illinois looks at where you are domiciled — voter registration, license, home, family — rather than counting days.

What counts as a day in Illinois?

Any part of a day spent in the jurisdiction generally counts as a full day toward the test — landing at 11 p.m. counts the same as a full day. Most states apply a narrow exception for pure travel through the state.

Count your days automatically

DayLine tracks which state you’re in every day, counts your days against Illinois’s actual test, and builds the audit-ready record that protects you. All on your iPhone — nothing leaves your device. Free for 30 days.

Related jurisdictions

This page provides general educational information about residency rules, verified against state statutes and administrative guidance at the time of writing. It is not tax, legal, or accounting advice; rules change and residency determinations depend on your complete circumstances. Consult a qualified tax professional.  ·  All jurisdictions  ·  DayLine home