Tax residency rules, audits, and the severance record (2026)
2026.1 Edition · Revised 2026-07-24 · DomusDay Research
Moving out of Illinois is easy. Stopping Illinois taxes is a different act, and it happens on paper: Illinois keeps treating you as a resident until the record shows otherwise, and the burden of showing otherwise is on the taxpayer asserting the change; only one domicile at a time.
There is no day-count to get under. Illinois defines a resident as anyone in the state for other than a temporary or transitory purpose, or domiciled in Illinois but absent for a temporary or transitory purpose. There is no fixed day threshold — the facts decide, and temporary absences expressly include wintering or summering out of state. That makes the evidence trail — where the pattern of an actual life points — the entire case. Everything on this page exists to answer one question: if IDOR asks, does your record hold?
Illinois residency is facts-based: temporary or transitory purpose and domicile, with no fixed threshold. The instructions expressly treat wintering out of state as a temporary absence that keeps residency intact.
Source ↗A prior-year Illinois resident present in Illinois more days than in any other state is presumed still a resident — a comparison against every state, rebuttable only by clear and convincing evidence.
Source ↗Illinois taxes estates above a $4 million exclusion — well below the federal level — and a deceased spouse's unused exclusion does not carry over. Domicile at death is the operative fact the residency record ultimately serves.
Source ↗Since 2020, nonresidents performing significant service in Illinois for more than 30 working days owe Illinois tax on the Illinois-workday share of wages, with employer withholding required.
Source ↗Illinois defines a resident as anyone in the state for other than a temporary or transitory purpose, or domiciled in Illinois but absent for a temporary or transitory purpose. There is no fixed day threshold — the facts decide, and temporary absences expressly include wintering or summering out of state. Days still matter — not as a threshold to duck under, but as evidence of where the year was actually lived, and as the trigger for the presumptions below.
Selling the apartment is not the test, and neither is the new driver's license. Illinois presumes an established domicile continues until it is shown to have changed — clear and convincing evidence to overcome the residency presumptions, with the burden on the taxpayer asserting the change; only one domicile at a time. Examiners weigh 4 primary factors — true, fixed, permanent home, family connections, business connections, social connections — and they weigh what you did, not what you intended. The pattern of an actual life somewhere else is the evidence; everything else is secondary.
A clean exit does not end every Illinois claim. These rules keep taxing specific situations after the move — each one is a way the state stays in your return.
AffectsFormer residents who keep working Illinois days for an Illinois employer.
AffectsOwners of Illinois businesses and pass-throughs, and workers with Illinois days.
AffectsMovers to the four reciprocal states who keep Illinois wages.
Illinois Department of Revenue (IDOR) runs a moderate-intensity residency program. IDOR publishes a general audit process with document-verification review; it publishes no residency-specific audit guidance or counts. An examination is not an argument about intentions — it is a request for documents, and the request looks like this:
Every item on that list either exists in your records from the year of the move, or it does not. That is the whole game — and why the severance record below is the section that matters most.
An audit years from now is answered with documents generated in the months around the move. This is that inventory — grouped the way examiners think about a life, each item paired with the evidence it leaves behind.
The first year after the move matters twice: the comparative-day presumption compares Illinois days against every other state for prior-year residents, and the homestead exemption claim — if not terminated — presumes Illinois residency on its own.
The license state is part of the evidence overcoming the residency presumptions.
Voter registration is among the evidence the regulation lists for rebutting the presumptions.
Source ↗Vehicle registration location corroborates the claimed change.
Professional licenses and work assignments are listed evidence for the residency determination.
Source ↗The Illinois homestead exemption claim creates a residency presumption — its termination date is part of the record.
Source ↗Keeping an Illinois home feeds the comparative-day presumption and the temporary-absence rule — snowbird patterns are expressly addressed in the instructions.
Source ↗The comparative-day presumption compares Illinois days against every other state — the first post-move year's day pattern carries particular weight.
Source ↗Financial account locations and activity show where daily life occurs.
Professional relationships — accountants, attorneys, physicians — contribute to the connections pattern.
Social, civic, and religious connections are enumerated in the regulation's residency analysis.
Source ↗The location of vehicles and significant possessions after the move corroborates the change.
Illinois expects IL-1040 with Schedule NR for the change year, allocating income between the resident and nonresident periods.
Source ↗Every rule on this page traces to one of these. When a blog and a statute disagree, the statute wins — start here.
How these are chosen, what the automated gates catch, and what this site deliberately does not do: how these guides are made →
The year of the move is filed on IL-1040 + NR, with income split between the resident and nonresident periods — and that return is itself evidence: it states your change date on a signed document. Employers withhold Illinois tax on Illinois-workday wages of nonresidents beyond 30 working days; reciprocal-state residents file IL-W-5-NR for exemption.
There is no fixed number. Illinois residency is facts-based — temporary or transitory purpose and domicile — and a prior-year resident present in Illinois more days than in any other state is presumed still a resident.
The taxpayer, by clear and convincing evidence overcoming the regulation's presumptions — with voter registration, licenses, work assignments, and the terminated homestead exemption claim among the listed evidence.
IL-1040 with Schedule NR — one schedule serves both part-year residents and nonresidents, taxing everything from the resident period plus Illinois-source income afterward.
Only if domicile actually changes: the estate tax reaches Illinois-domiciled decedents above the $4 million exclusion, with no spousal portability. The same residency record that answers an income-tax audit answers this.
2026.1 Edition · Revised 2026-07-24 · DomusDay Research