Idaho Tax Residence: the rule, how days are counted, examples

Summary

Idaho treats you as a resident for income tax if you keep a home in Idaho for the entire tax year and spend more than 270 days of that year in the state. This applies even when your permanent home in law is in another state. Any part of a calendar day in Idaho counts as a day, unless you can show that you were there that day for a temporary purpose. A resident is taxed on all income, including income from outside Idaho. The rule is in Idaho Code section 63-3013 and is applied by the Idaho State Tax Commission.

Limit: 270 days. Day 271 is the first day over the limit
Period: The tax year, for most people 1 January to 31 December
A day counts when: You are in Idaho for any part of the calendar day
Second condition: You keep a home in Idaho for the entire tax year
Law: Idaho Code section 63-3013
Run by: Idaho State Tax Commission

Who it applies to

People who keep a legal home in Washington, Nevada, Wyoming or Alaska, states with no tax on wages, and live in Idaho for most of the year.
Seasonal business owners with a home in Idaho and a home in another state.
Retired people who own a house in Idaho all year and travel in winter.
People from Idaho who work outside the state for more than a year and want to know when Idaho stops taxing them.

The rule

Idaho Code section 63-3013 gives two ways to be a resident. The first is to be domiciled in Idaho for the entire taxable year. Domicile is the place where you have your true, fixed, permanent home and main establishment. The second is to maintain a place of abode in Idaho for the entire taxable year and spend in the aggregate more than 270 days of the taxable year in the state. The Tax Commission puts it simply: you keep a home in Idaho for the entire tax year and spend more than 270 days of the year in Idaho.

The Idaho limit is much higher than the 183 days used by many states, and the home condition is stricter: the home must be kept for the whole year, not for part of it. Both conditions must be met.

The statute says how to count. Presence within the state for any part of a calendar day is a day spent in the state, unless you can show that your presence on that day was for a temporary or transitory purpose. So the starting point is that every day counts, and it is for you to show that a day was only a visit.

A person who does not meet these tests for the full year can still be a part-year resident. Under the Tax Commission's guide this includes a person who changes domicile to or from Idaho during the year, and a person who has a home in Idaho and is there for more than a temporary reason. The guide asks whether you are in Idaho more than 90 days, and whether you have business, financial, family or social ties there. If so, you must show that your stay is like that of a visitor or a person on holiday.

Section 63-3013 also has a rule for people who leave. A person is not a resident during a period of absence that starts with at least 445 days outside Idaho in the first 15 months, as long as the conditions in the statute are kept.

Why it exists

Idaho borders several states that do not tax wages, and people can easily keep a legal home across the border. Idaho taxes residents on all their income, so it needs a test that does not depend only on where a person says home is. The lawmakers chose a narrow test: only a person who keeps a home in Idaho all year and is there for nearly three quarters of the year is treated as a resident against his or her stated domicile.

Counting the days

You count the calendar days of the tax year on which you were in Idaho for any part of the day. Days that you can show were for a temporary purpose can be left out.

Take the tax year. For most people this is 1 January to 31 December.
Mark every calendar day on which you were in Idaho for any part of the day.
Decide whether any days were only for a temporary purpose, such as passing through, and whether you can prove it. Leave out only the days you can prove.
Add the days and compare with 270. At 271 days or more the day condition is met.
Check the home condition: did you keep a home in Idaho from the first day to the last day of the tax year?
If either condition fails, check whether you are a part-year resident instead.

How Countr counts it. Countr counts every calendar day on which your phone records you in Idaho, from 1 January to 31 December, and compares the total with 270. Any part of a day counts as a full day, as the statute says. Countr starts to warn you 14 days before the limit. The app is simpler than the law in two ways. It cannot know whether a day was for a temporary purpose, so it counts every day, and the warning can come early, never late. And it cannot see whether you kept a home in Idaho for the entire tax year. That condition is for you to judge, so add this tracker only if you keep a home in Idaho all year. Countr does not track the 445-day absence rule.

Track Idaho Tax Residence on your phone.

Countr finds your past trips in your photos and keeps counting from there.

Download on the App Store

Examples

A Coeur d'Alene house and a Washington address

Linda and Jeff say their domicile is Spokane, Washington, where they rent a small flat. They own a house in Coeur d'Alene, Idaho, and keep it all year. In 2026 they live in the Idaho house from 1 March to 15 December, which is 290 days. They kept a home in Idaho for the entire year and spent more than 270 days there, so they are Idaho residents for 2026, and Idaho taxes all their income.

A home bought in February

Pablo is domiciled in Nevada. He buys a house in Boise on 10 February 2026 and is in Idaho on 300 days that year. He passes 270 days, but he did not keep a home in Idaho for the entire tax year, so the 270-day test is not met for 2026. This does not make him a nonresident. He has a home in Idaho and is there for more than a temporary reason, so under the Tax Commission's guide he should look at part-year resident status. For 2027 he will own the home all year.

Day 270 falls on 27 September

Erin keeps a house in Sandpoint all year and is domiciled in Wyoming. She is in Idaho from 1 January 2026 without a break. January to September has 273 days, so 27 September is her day 270. If she leaves that evening and does not return in 2026, she has not spent more than 270 days. If she stays one more day, 28 September is day 271 and the day condition is met.

Exceptions

A day does not count if you can show that your presence in Idaho on that day was for a temporary or transitory purpose. The burden is on you.
A person who is absent from Idaho for at least 445 days in a 15-month period is not treated as a resident during the absence. After that, the person becomes a resident again when he or she is in Idaho for more than 60 days in a calendar year.
The 445-day rule is not available if you have a permanent home in Idaho where your spouse or minor children live for more than 60 days in a calendar year, or if you claim Idaho as your tax home on your federal return.
The 445-day rule is also not available to staff of a United States Senator or Representative, or to holders of an elected or appointed United States Government office, other than members of the armed forces and career members of the Foreign Service.
For members of the armed forces, residence follows domicile. A service member domiciled in another state and stationed in Idaho is a military nonresident, and active duty military pay is not taxed by Idaho.
Under Idaho's administrative rule 35.01.01.030, the 445-day exception does not apply to a service member, or the spouse of one, who is domiciled in Idaho when the federal Servicemembers Civil Relief Act applies.

Common misconceptions

“Idaho uses the 183-day rule.”: Idaho's limit for people domiciled elsewhere is more than 270 days, together with a home kept in Idaho for the entire tax year. There is no 183-day test in section 63-3013.
“Under 270 days means Idaho cannot tax me as a resident.”: If you are domiciled in Idaho, the day count does not matter. And a person with a home in Idaho who is there for more than a temporary reason can be a part-year resident with far fewer days.
“A visit of a few hours is not a day.”: The statute counts presence for any part of a calendar day as a day, unless you can show that the presence was for a temporary or transitory purpose.
“I left Idaho for a job, so I stopped being a resident on the day I left.”: If you stay domiciled in Idaho, you stay a resident unless you meet the absence rule: at least 445 days out of Idaho in a 15-month period, with its other conditions.

Questions and answers

Do I need a home in Idaho for the 270-day rule to apply?

Yes, and for the whole tax year. The statute asks for a place of abode maintained in Idaho for the entire taxable year. A home that you bought or first rented during the year does not meet this for that year.

Does the day I arrive in Idaho count?

Yes, as a starting point. Presence for any part of a calendar day is a day spent in Idaho. You can leave out a day only if you can show that you were there for a temporary or transitory purpose.

What happens if I spend 271 days in Idaho?

If you also kept a home in Idaho for the entire year, you are an Idaho resident for that year. The Tax Commission says Idaho taxes all of a resident's income, including income from sources outside Idaho.

I am in Idaho only 100 days each summer. Can I be taxed?

You are far under 270 days, so the full-year test is not met. But the Tax Commission asks people who are in Idaho for more than 90 days to show that the stay is like a holiday. In its own example, a couple with 100 summer days, no work in Idaho and nonresident fishing licences were nonresidents.

How does the 445-day rule work?

It is for people who leave Idaho. If you are out of Idaho for at least 445 days in the first 15 months after leaving, you are not treated as a resident during the absence and may not have to file an Idaho return. You become a resident again when you are in Idaho for more than 60 days in a calendar year.

Can spouses have different Idaho status?

Yes. The Tax Commission says spouses can have separate residences and domiciles. Each spouse counts his or her own days. If they file a joint federal return, they must file a joint Idaho return.

Sources

Other rules for United States

Arizona Tax Residence 273 days in each calendar year
California Tax — Visitors 181 days in each calendar year
California Tax Residence 273 days in each calendar year
Connecticut Tax — 30 Days or Fewer 30 days in each calendar year
Connecticut Tax Residence 183 days in each calendar year
Delaware Tax Residence 183 days in each calendar year
Hawaii Tax Residence 200 days in each calendar year
Iowa Tax Residence 183 days in each calendar year

See all trackers

This page explains the rule and how the days are counted. It is not legal or tax advice. The authority decides each case on its own facts.