Tax residency rules, audits, and the severance record (2026)
2026.1 Edition · Revised 2026-07-25 · DomusDay Research
Moving out of Idaho is easy. Stopping Idaho taxes is a different act, and it happens on paper: Idaho keeps treating you as a resident until the record shows otherwise.
On the burden of showing otherwise: Where an absence is claimed, the statutory exception carries its own arithmetic: an individual is not a resident for a period of absence of at least 445 days in the first 15 months, provided the individual was not present in the state more than 60 days in any calendar year of the remaining absence — and the exception is unavailable where a permanent home in Idaho houses a spouse or minor children for more than 60 days in a calendar year.
Two tests decide it. Cross 270 days with a Idaho abode still available and you are taxed as a resident regardless of where you claim to live — and any part of a day counts. Or keep the day count clean but leave the life-pattern evidence pointing at Idaho, and domicile does the same work. Everything on this page exists to answer one question: if Tax Commission asks, does your record hold?
A place of abode maintained in Idaho for the entire taxable year plus more than 270 aggregate days in the state makes a person a resident regardless of domicile. Presence for any part of a calendar day counts unless it was for a temporary or transitory purpose.
Source ↗An absence of at least 445 days across 15 months takes an individual out of resident status, with no more than 60 days in Idaho in any calendar year of the remaining absence. It is unavailable where an Idaho permanent home is occupied by a spouse or minor children more than 60 days in the year.
Source ↗Idaho allows a deduction of up to 60% of capital gain net income from the sale or exchange of qualifying Idaho property, computed on Form CG. Real property qualifies where held at least 12 months and sold on or after January 1, 2005.
Source ↗The Tax Commission maintains a Residency Audit Manual for examiners and issues written residency decisions. For a state its size, that is an unusual amount of published residency-specific guidance — and it tells a mover exactly which facts get examined.
Source ↗This is the test with a number in it, and the number is what an auditor can verify line by line. Keep any Idaho dwelling suitable for year-round use and spend more than 270 days in the state, and Idaho taxes all of your income — domicile arguments never enter into it. Any part of a day counts: a morning meeting, a connection through the city with a dinner on the ground, a single evening — each is a full day against the threshold.
Two prongs: domicile in Idaho for the entire taxable year, or a place of abode maintained for the entire year plus more than 270 aggregate days in the state. The 270-day figure is unusual — most day-count states use 183 — and it is paired with a part-day counting rule that treats any part of a calendar day as a day.
A place of abode maintained in Idaho for the entire taxable year. Combined with more than 270 days in the aggregate spent in Idaho, it makes an individual a resident even where domicile is in another state. Both elements run for the entire taxable year — the statute pairs 'maintains a place of abode in this state for the entire taxable year' with the aggregate day count, so a mid-year arrival or departure generally falls to part-year treatment instead.
Selling the apartment is not the test, and neither is the new driver's license. Idaho presumes an established domicile continues until it is shown to have changed — domicile in Idaho for the entire taxable year makes an individual a resident; the Tax Commission applies the standard through its published Residency Audit Manual. On the burden: Where an absence is claimed, the statutory exception carries its own arithmetic: an individual is not a resident for a period of absence of at least 445 days in the first 15 months, provided the individual was not present in the state more than 60 days in any calendar year of the remaining absence — and the exception is unavailable where a permanent home in Idaho houses a spouse or minor children for more than 60 days in a calendar year. Examiners weigh 4 primary factors — a place of abode maintained in idaho, aggregate days in idaho, length of the absence, whether a spouse or minor children live in an idaho permanent home — 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 Idaho claim. These rules keep taxing specific situations after the move — each one is a way the state stays in your return.
AffectsMovers on long assignments abroad or out of state, and anyone whose family stays behind in the Idaho house.
AffectsAnyone keeping an Idaho home after moving, especially those returning for work or seasonal stays.
AffectsLeavers who keep Idaho workdays, Idaho rental or business property, or an Idaho business interest.
AffectsMovers holding Idaho real property or other qualifying Idaho property at the time of the move.
Idaho State Tax Commission (Tax Commission) runs a high-intensity residency program. Idaho publishes a Residency Audit Manual for its examiners and issues written residency decisions — a level of published residency-specific guidance few states of its size produce. 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.
Two numbers matter and neither is 183. The residency prong is 270 aggregate days paired with an Idaho abode maintained for the entire year, counted a part-day at a time unless the presence was temporary or transitory. The absence rule is 445 days across 15 months, with the further condition of no more than 60 days in the state in any calendar year of the remaining absence — and it is unavailable outright where a spouse or minor children occupy an Idaho permanent home for more than 60 days in the year. The change year is filed on Form 43 with Form 39NR.
Idaho ties driver licensing to residence, with the residency definition for licensing and registration set at 30 days since July 1, 2024; the destination state's license is the matching dated record on the way out.
Source ↗Idaho registration follows residence; registering vehicles in the new state produces dated records there and closes the Idaho registration.
Source ↗Idaho voter registration requires 30 days of Idaho residence; registering in the new state supersedes it with a dated record there.
Source ↗A place of abode maintained in Idaho for the entire taxable year is half of the statutory test; what happened to the Idaho home, and when, is the fact that removes that half.
Source ↗Where a permanent home in Idaho is occupied by a spouse or minor children for more than 60 days in a calendar year, the 445-day absence exception is unavailable — so who lives in the Idaho house is a counted fact.
Source ↗The homeowner's exemption applies to an owner-occupied primary residence and is applied for with the county assessor between January 1 and April 15 each year; the county record shows which years it was claimed.
Source ↗Banking and advisory relationships moved to the new state corroborate that the Idaho presence, where it continues, is temporary or transitory.
Idaho workdays after the move drive both the day count and Idaho-source income, which requires a nonresident return above $2,500 of Idaho gross income.
Source ↗Qualifying Idaho property retained after the move keeps the Form CG deduction in view — real property qualifies where held at least 12 months and sold on or after January 1, 2005.
Source ↗Physicians, dentists, and advisers engaged in the new state generate dated, located records on the departure side.
Congregations, clubs, and civic involvement relocated out of Idaho are dated evidence about where life is centered.
Where household goods and vehicles went corroborates that the Idaho abode was given up rather than kept available.
Idaho counts any part of a calendar day as a day in the state unless the presence was for a temporary or transitory purpose, so the departure-year record needs day-level detail rather than month-level summaries.
Source ↗The change year is filed on Form 43 with the Form 39NR supplemental schedule, allocating income between the residency and nonresidency 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 Form 43, with income split between the resident and nonresident periods — and that return is itself evidence: it states your change date on a signed document. Idaho applies one rate to residents, part-year residents, and nonresidents, so withholding follows where income is sourced rather than a separate nonresident schedule.
More than 270 in the aggregate, paired with a place of abode maintained in Idaho for the entire taxable year. Presence for any part of a calendar day counts as a day unless the individual shows it was for a temporary or transitory purpose — so partial days and short trips are inside the count.
There is a rule for exactly that: an absence of at least 445 days in the first 15 months, with no more than 60 days in Idaho in any calendar year of the remaining absence. It is unavailable where a permanent home in Idaho is occupied by a spouse or minor children for more than 60 days in a calendar year.
At the ordinary 5.3% rate, except that up to 60% of capital gain net income from qualifying Idaho property is deductible on Form CG. Real property qualifies where held at least 12 months and sold on or after January 1, 2005 — the qualification runs with the property rather than the seller's residency.
Idaho-source income, where total gross income from Idaho sources is more than $2,500 — reported on Form 43 with the Form 39NR supplemental schedule. That covers Idaho workdays, Idaho rental and business income, and gains on Idaho property.
Form 43, the part-year resident and nonresident return, filed with Form 39NR. Part-year residents can claim a prorated credit against tax due but do not receive a refund of any excess credit.
The residency definition for a driver's license, identification card, title, or registration is 30 days, reduced from 90 in July 2024. Voter registration opens after 30 days of Idaho residence, with registration also available at the polls on election day. The homeowner's exemption is applied for with the county assessor between January 1 and April 15.
2026.1 Edition · Revised 2026-07-25 · DomusDay Research