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.
Day-counting is the physical-presence half of a state residency analysis. The other half is domicile, which is a legal concept. This post is about the physical side: what the 183-day rule actually says, how states count days, what day-counting does not protect you from, and how to build a location log that will survive a Washington DOR audit.
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: more-than-half-the-year test.
Washington has not yet adopted a specific ESSB 6346 statutory-residency test, but the capital gains tax and estate tax use a similar structure, and implementing regulations will likely follow the 183-day template. Until those regulations issue, assume 183 days is 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" face aggressive audits. 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.
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.
For the full relocation playbook, see How to Leave Washington. For the legal framework, see Domicile vs. Residency.
Last reviewed: April 16, 2026. Nothing in this article is legal or tax advice.
