US-IL
Illinois tax residency rules
Threshold: 183 days · Day Count · Calendar year (Jan 1 – Dec 31)
Illinois has a 4.95% flat tax. Residency is domicile-based with a 'temporary or transitory purpose' standard rather than a clean day-count rule. Cook County's homestead exemption and Chicago's lifestyle taxes interact with residency status.
- No 183-day statutory residency rule like NY or NJ.
- Long-term business presence in IL can trigger residency under the 'temporary or transitory' test.
- Document IL days carefully even though IL doesn't apply a hard threshold.
Rules tracked by Tax Days
IL 183-Day Rule
- Type
- Day Count
- Threshold
- 183 days
- Period
- Calendar year (Jan 1 – Dec 31)
Tax residency triggers if you're physically present for more than the threshold number of days in a calendar year.
You are a statutory resident of Illinois if you spend more than 183 days in the state.
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