Reviewed August 24, 2026. Washington has still not published an interpretive regulation defining “day” for ESSB 6346 purposes, so the any-part-of-a-day approach below remains a planning assumption rather than a rule. Initiative 645, which would repeal the income tax, is on the November 3, 2026 ballot; a Supreme Court commissioner denied emergency relief on the ballot disclosure on August 20, 2026, and the separate constitutional challenge to the tax remains pending with no injunction. Plan as though the tax arrives on schedule.
Ask a founder planning to leave Washington how they will prove they left, and you will often get a version of this answer: "I'll spend fewer than 183 days a year in Washington." That answer is close to right — and it is also nowhere near complete.
This page is about one prong: the non-domiciliary route into Washington residency. ESSB 6346 §101(8) and RCW 82.87.020 make you a resident either by domicile or — if you are not domiciled here — by maintaining a place of abode in Washington and being physically present more than 183 days. The day count is the second of those. It is not a way out of the first.
So the practical rule: if you are still domiciled in Washington, counting days to stay under 183 does nothing. You are already a resident on the domicile prong, and the day count never comes into play. Day-counting matters once your domicile has genuinely moved and you need to avoid being pulled back in as a statutory resident — or when you are testing the 30-day safe harbor, which is a different threshold on a different prong.
For the safe harbor that applies while you are still domiciled here, see Washington's 30-Day Rule. For the move itself — changing domicile, and the record that proves it — see How to Leave Washington.
What the 183-day rule actually is
Most states that tax nonresident income operate a statutory residency rule alongside their common-law domicile rule. The statutory rule typically says: if you (1) maintained a permanent place of abode in the state during the tax year and (2) spent more than a specified number of days there, you are treated as a resident for the year — regardless of where your domicile is.
The specified number is usually 183 days (roughly half the year plus one), though the exact threshold and definitions vary:
- New York: 183+ days plus a permanent place of abode.
- California: nine-month "presumption" plus a common-law domicile test.
- Illinois: no day-count test at all — residency turns on domicile and a temporary-or-transitory-purpose standard (86 Ill. Adm. Code 100.3020), a reminder that not every state draws a bright line.
Washington’s income tax adopts this structure directly. ESSB 6346 §101(8) defines "resident" to include both a Washington domiciliary (subject to a narrow safe harbor for a domiciliary who keeps no abode here, maintains one elsewhere, and spends 30 or fewer days in the state) and a non-domiciliary who maintains a place of abode in Washington and is physically present more than 183 days. That mirrors the Washington State capital gains tax (RCW 82.87.020). What is still pending is DOR interpretive regulation — the income-tax analog to WAC 458-20-301 — so treat 183 days as the ceiling, not the target, and plan well below it.
What counts as a "day"
Every state that uses a day-count rule has to define "day," and the definitions are not the same:
- Any part of a day rule (most states, including New York): if you were physically present in the state for any part of a calendar day, that day counts as a day in the state.
- Overnight rule: you have to sleep in the state for the day to count.
- Transit exception: time in an airport connection or on a through train generally does not count.
- Medical exception: days in a hospital for emergency medical care typically do not count.
Washington has not yet defined its "day" for ESSB 6346 purposes. Plan for the any-part-of-a-day rule, because it is the more taxpayer-unfriendly of the two and because it is the rule the most aggressive states apply. If the final regulation is more generous, your records will still support the more generous rule. The reverse is not true.
Practical consequences of the any-part-of-a-day rule:
- A one-hour Seattle stopover on a trip from Vancouver to Austin counts as a Washington day.
- Driving from Portland to Vancouver, B.C. through I-5 Washington territory for seven hours counts as a Washington day (unless exempted by a specific transit rule).
- Flying in at 11:58 p.m. and flying out at 12:02 a.m. counts as two Washington days.
These seem absurd, and they are. They are also how the rule actually works.
The "permanent place of abode" trap
Statutory residency requires both 183+ days and a permanent place of abode. The place-of-abode element is frequently underestimated.
A permanent place of abode is a dwelling you maintain that is suitable for year-round living. You do not have to own it. You do not have to sleep in it. You merely have to maintain it in a way that would make it habitable if you wanted to stay.
In New York, this rule is how auditors have pulled back to New York residency people who "moved out" but kept a pied-à-terre they rarely used. A second home you have not used in six months is still a permanent place of abode. A houseboat registered to you in Lake Union counts.
Practical implication: if you are planning to sever Washington statutory residency, you have to be very thoughtful about keeping any Washington property that qualifies as a permanent place of abode. At a minimum, document use patterns carefully. At a maximum, divest.
Day-counting does not solve domicile
Here is the most important point in this entire post: passing the day-count test does not mean you have changed domicile. It means you have not triggered statutory residency under the day-count test alone. Your domicile analysis is a separate question.
A taxpayer who spends 150 days a year in Washington, has their family in Seattle, works primarily from a Seattle office, banks primarily at a Seattle bank, and has a Seattle primary care physician is almost certainly a Washington domiciliary. The 33 days under 183 gets them out of one trap. It does nothing about the other.
This is the single most common mistake made by high earners planning a residency change: treating day-counting as the whole game when it is only half.
What your location log should contain
Start your log the moment you move — ideally the day before. It should be simple, chronological, and contemporaneous. For each calendar day from the move date forward, record:
- Date.
- State (and city) where you slept.
- States entered during the day.
- Start and end of any flight, and flight numbers.
- Brief notes on any Washington time (for example, "flew through SEA at 3pm, departed 4pm for AUS").
Back the log up with passive evidence that can verify it without your cooperation:
- Credit card statements with transaction locations.
- Cell phone bills showing calls and data usage by cell tower.
- Toll transponder records (E-ZPass, SunPass, FasTrak, TxTag).
- Calendar exports.
- Flight confirmations and boarding passes.
- Hotel folios and Airbnb receipts.
- Gas station receipts.
If audited, you want to be able to hand your counsel a single file and walk away. Reconstructing the log from scratch years later under audit pressure is how people lose.
Specific traps for Washington taxpayers
- The Vancouver/Portland commuter. If you live in Vancouver, Washington and work in Portland, Oregon, you are a Washington resident regardless of day-counting. Moving across the river is not a residency change.
- The Boise/Spokane split. Spokane residents who "spend a lot of time in Idaho" should expect that claim to be tested against the day count and the place-of-abode test. The commute pattern matters.
- The second-home owner. Washington ski, lake, and ferry-access cabins are habitable year-round. They are permanent places of abode under any-part-of-a-day rules.
- The weekender. A Seattle apartment rented solely for weekends when the family visits, combined with 140 days of weekend trips, lands you uncomfortably close to statutory residency plus maintains a Washington abode.
Where day-counting actually decides the answer: art, cars, and collectibles
Everything above concerns stock and other intangibles, where RCW 82.87.100(1)(b) allocates the gain by domicile at the time of sale and the day count is beside the point. Tangible personal property runs on a different rule, and it is the one place in this analysis where physical facts — the asset's and yours — do the work.
Under RCW 82.87.100(1)(a), gain on tangible personal property is allocated to Washington if the property was located in Washington at the time of the sale. That is a fact about the asset, not about you. A nonresident who sells a painting hanging in a Seattle house is inside the tax.
If the property sits outside Washington at closing, Washington reaches the gain only if all three of these are true: the property was in Washington at some point during the sale year or the year before; you were a resident when the sale occurred; and no other taxing jurisdiction taxed the gain.
Read the second element carefully. It says resident, not domiciliary — and “resident” is the defined term in RCW 82.87.020, satisfied either by domicile or by the abode-plus-183-days test this page is about. So for a collector who has genuinely moved: get the asset out of Washington before closing, and the first branch is gone. The day count is then one of the two ways back in, and the 30-day safe harbor is the other.
The sequencing, and why the 30-day rule is worth more here than anywhere else in the statute, is worked through in Sell the House, Ship the Ferraris.
The bottom line
Aim for fewer than 120 Washington days per calendar year as a comfort zone below any plausible 183-day threshold. Divest Washington properties that qualify as year-round abodes, or at least establish clear non-use patterns. Keep a contemporaneous log from day one. And remember — day-counting is the floor, not the ceiling. Your domicile analysis must also pass.
The 30-day safe harbor works in tandem with the 183-day rule — but the two tests apply to different people. For a full breakdown of when the 30-day rule applies (and when it doesn't), see Washington's 30-Day Rule for Tax Residency: What It Actually Means.
For the full relocation playbook, see How to Leave Washington. For the legal framework, see Domicile vs. Residency.
Frequently asked questions
Do I have to spend a minimum number of days in my new state to establish domicile there?
No. No state imposes a minimum day count to establish domicile. Domicile is your true fixed home — physical presence plus intent to remain indefinitely — and it can attach the day you arrive in Nevada, Texas, or Florida. Day-counting runs the opposite direction: the 183-day and 30-day thresholds belong to the state you are leaving, as a second route to tax you even after you are domiciled elsewhere. Washington can still treat you as a resident if you keep a place of abode in Washington and spend more than 183 days in-state during the year (RCW 82.87.020), whatever your new domicile. The days that count against you are Washington days, not new-state days.
Does spending fewer than 183 days in Washington make me a non-resident?
No. The 183-day rule is one of two tests. Even if you pass it, Washington can still claim you as a resident under the common-law domicile test — based on where your home, family, work, and life are. Pass both tests, or you have not changed residency.
What counts as a "day" in Washington for residency purposes?
Washington has not yet defined "day" for ESSB 6346 purposes. Plan for the any-part-of-a-day rule that most aggressive states apply: if you are physically present in the state for any part of a calendar day, the day counts. A one-hour SEA stopover counts. Plan to the strictest rule and your records will support a more generous one.
What is a "permanent place of abode"?
A dwelling you maintain that is suitable for year-round living. You do not have to own it, sleep in it, or use it. A ski cabin, lake house, or pied-à-terre that is habitable counts. Keeping any qualifying Washington property complicates a residency change.
How many days in Washington is safe?
Aim for fewer than 120 calendar days per year as a comfort zone well below the 183-day threshold. The exact safe number depends on the strength of your domicile facts in the new state — the weaker the new-state facts, the lower your Washington day count needs to be.
How we can help
Day-counting strategy and the broader residency-change record are best built early — before the move, not after the audit. If you are actively planning a Washington exit, build the file while the facts still support the story you want to tell.
Book a 20-minute planning call →
Last reviewed: August 24, 2026. This article is for general educational purposes only and does not constitute legal or tax advice.
