Washington's 183-Day Rule: How Tax Residency Actually Works

Reviewed September 21, 2026. See the enacted law and the Initiative 645 tracker for repeal and litigation developments.

How Long Do You Have to Live in Washington to Be a Resident?

There is no single day count for all purposes. Washington’s existing capital gains tax uses the resident definition in RCW 82.87.020(11). The separate income tax scheduled to begin January 1, 2028 uses RCW 82A.04.010(8). Both treat Washington domicile as an independent residency basis, subject to the statutory exception. Separately, someone not domiciled in Washington during the taxable year can qualify by maintaining a Washington place of abode and being physically present for more than 183 days that year. Staying below that day count does not resolve domicile. Resident status also does not answer every asset-allocation question. For the broader framework, see the income-tax guide.

This page focuses on that non-domiciliary abode-and-day-count route. Washington domiciliaries must separately consider the 30-day safe harbor and its full-year abode conditions. Washington-source income can remain taxable even to a nonresident.

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 and the Washington domicile-change checklist.

What Is Washington's 183-Day Rule?

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.

For the 2028 income tax, RCW 82A.04.010(8)(c) addresses the resident portion of the year by reference to domicile or maintaining an abode. The capital-gains tax has its own residency and asset-allocation provisions; apply the correct statute to each tax.

What Counts as a Day in Washington?

Day definitions and exceptions are jurisdiction-specific. Do not import another state’s rules into Washington:

• Partial calendar days: Washington’s income-tax statute expressly counts a calendar day or any portion of one for its residency definition.
• Overnight records: where you slept is useful evidence, but sleeping elsewhere does not erase a partial Washington day.
• Transit: do not assume that an airport connection or drive through Washington is excluded. Identify applicable authority before claiming an exception.
• Medical visits: do not assume a hospital day is excluded merely because another jurisdiction provides medical relief.

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.

The Washington place-of-abode requirement

The non-domiciliary income-tax route requires a Washington place of abode and physical presence for more than 183 days. Exactly 183 days does not satisfy that numerical condition. The statute uses “place of abode” in this route and “permanent place of abode” in the domiciliary safe harbor; keep those provisions distinct.

A retained dwelling can be important to both abode and domicile analysis. Examine its availability, suitability, maintenance and the taxpayer’s actual relationship to it under the relevant tax. Lack of ownership or infrequent use does not by itself resolve the question.

A second home, apartment, cabin or houseboat can require close review. Do not conclude that every vessel registration or unused property automatically satisfies the statutory abode element. Document the actual facts and the governing rule.

Keeping a Washington dwelling does not automatically prevent a domicile change or establish statutory residency. Review the dwelling’s availability and use, your Washington days, and the applicable residency test together.

How Does Washington Domicile Work?

Consider a taxpayer who spends 150 days a year in Washington, has family in Seattle, works primarily from a Seattle office, banks locally, and has a Seattle physician. Those connections support Washington domicile, but the conclusion depends on the full facts, including the taxpayer’s actual home and intent. Staying below 184 days does not resolve that inquiry.

The specified number is usually 183 days (roughly half the year plus one), though the exact threshold and definitions vary:

• New York: generally more than 183 days plus the applicable permanent-place-of-abode requirements; exactly 183 is not more than 183.
• California: California treats an individual as resident if present for other than a temporary or transitory purpose, or domiciled in California but absent for a temporary or transitory purpose. Spending more than nine months in California creates a rebuttable residency presumption; spending less does not establish nonresidency. See California FTB Publication 1031, sections E and H.
• 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.

What your location log should contain

Keep a location log for the entire taxable year, not just the period after your move. The statutory day-count test measures Washington presence during the taxable year. If you start midyear, reconstruct earlier days from reliable records and identify any gaps. Record the dates of domicile changes and when you began or ceased maintaining each place of abode separately; those facts determine the applicable residency period. For each calendar day, 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.

Keep the log and supporting records together so counsel can reconcile your travel dates, living arrangements, and any gaps if your residency is examined.

When Four Disputed Days Mattered: The Robertson Case

In Matter of Julian H. and Josephine Robertson, DTA No. 822004 (N.Y. Tax Appeals Tribunal, Sept. 23, 2010), New York City statutory residency turned on four disputed days. The parties had already stipulated 183 New York City days and 179 non-City days; presence on any one of the remaining four would have crossed the “more than 183” line. The Tribunal affirmed cancellation of a roughly $26.7 million deficiency. Contemporaneous calendars and other location records—together with credible testimony—were central to proving which days counted.

That New York decision does not control Washington. Washington residency is tested under RCW 82A.04.010(8): domicile is an independent basis; a separate nondomiciliary track requires a Washington place of abode plus more than 183 days; and the 30-day domiciliary safe harbor is a different rule still. The transferable point is narrower: when a statutory day count is live and close to the line, contemporaneous location records can be outcome-determinative—which is why the log above matters.

Specific traps for Washington taxpayers

• The Vancouver/Portland commuter. Working in Oregon while keeping your actual home in Vancouver does not itself move your domicile out of Washington. An actual move across the river can change domicile; commuting across it is a different fact.
• 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. Review each Washington cabin or other dwelling’s availability and suitability. Do not assume all cabins are habitable year-round, or that the partial-day rule determines whether a property is an abode.
• The frequent visitor. Assume a person is domiciled outside Washington, maintains a Seattle apartment, and spends 140 calendar days or partial days in Washington during the taxable year. Those facts do not satisfy the more-than-183-day condition. Additional visits can change the count; Washington domicile and Washington-source income require separate analysis.

A Separate Capital-Gains Issue: Art, Cars, and Collectibles

For the capital-gains tax, distinguish stock and other intangibles from tangible property. RCW 82.87.100(1)(b) allocates intangible gain by domicile at sale. Tangible property follows a separate location-and-residency rule. The broader income-tax residency discussion above is not limited to stock sales.Under RCW 82.87.100(1)(a), long-term gain from tangible personal property is allocated to Washington if the property is located here at the sale or exchange. That location rule can apply even to a nonresident selling a painting in a Seattle house. Allocation is one step in the calculation: the asset’s tax treatment, applicable exemptions, deductions, losses, and credits determine whether tax is actually owed.

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.

The out-of-state tangible-property branch uses resident status, not domicile alone. Apply RCW 82.87.020’s residency definition, including the domiciliary safe harbor where all its conditions are met. The 30-day safe harbor can prevent resident status; it is not a separate route back into taxation. Moving the asset outside Washington removes the in-state-location branch but does not automatically defeat the remaining statutory conditions.

For a worked collection-sale example, see Sell the House, Ship the Ferraris. For the broader allocation framework, see the Washington capital-gains tax guide.

The bottom line

Keep a contemporaneous record of every Washington calendar day or partial day, and leave a practical margin below the more-than-183-day threshold where that test applies. No 120-day target is a statutory safe harbor.

Frequently asked questions

Do I have to spend a minimum number of days in my new state to establish domicile there?

There is no minimum new-state day count in Washington’s income-tax domicile definition. An actual move and intent to make the new location your permanent home are central, but state-specific rules still require review.

Does Spending Fewer Than 184 Days Make You a Nonresident?

No. Staying at or below 183 days avoids only the numerical condition of the non-domiciliary abode test. It does not resolve domicile or Washington-source income.

What counts as a "day" in Washington for residency purposes?

For the income-tax residency definition, RCW 82A.04.010(8)(b) defines a day as a calendar day or any portion of one. Partial days count under the enacted text. Record transit and other brief visits, and identify applicable authority before claiming any exception.

What is a "permanent place of abode"?

The income-tax domiciliary safe harbor refers to a permanent place of abode; the non-domiciliary statutory-residency route refers to a place of abode. A dwelling’s availability, suitability, maintenance and the taxpayer’s relationship to it require factual review. Mere non-use is not a universal exemption.

How we can help

Preserve accurate, contemporaneous evidence of your actual move, living arrangements, and Washington visits. Keep the records as events occur, identify any gaps, and review domicile, abode, and day-count questions before a planned sale.

Book a 20-minute planning call →

Last reviewed: September 21, 2026. This article is for general educational purposes only and does not constitute legal or tax advice.