Okay, first point, if you want to change your residency or domicile from Washington state to some other state? That’s a question you answer with the help of your attorney. Not your accountant. And not some blogger.
But if you’re curious about establishing residency in or changing your domicile to some new state? Maybe you want to avoid the Washington state capital gains tax? Or maybe you want your heirs to avoid the new higher Washington state estate taxes? (Click here to learn about the new higher tax.) Washington provides a useful form for thinking about these issues: Form 85-0045, the Affidavit Substantiating Decedent’s State of Domicile at Death.
The General Washington Residency Rule to Start
Let’s start with the general residency rule, though, which comes from the Revised Code of Washington (RCW 83.100.020), the Washington Administrative Code (WAC 458-57-105), and ironically from the Department of Revenues FAQ (click here).
Residents potentially owe estate and capital gains tax returns. And residents are people domiciled in Washington state.
So what is a person’s domicile? Quoting ChatGPT, “’Domicile’ means a person’s true, fixed, and permanent home and place of habitation. It is the place the person intends to return to whenever absent. A person can have only one domicile at a time”.
The state applies a facts and circumstances test and basically looks at all the common-sense stuff you would look at if your job was determining people’s domiciles. But you and I get a concrete sense of what matters from that Form 85-0045.
The actual form appears here: Affidavit Substantiating Decedent’s State of Domicile at Death. And for background, a personal representative, or executor, might fill out and provide this form to the state’s Department of Revenue if he or she needs help determining domicile.
But the other useful thing? The form helps you think concretely the mechanics of possibly changing your domicile.
Reviewing Form 85-0045
A first tip to start: Go ahead and grab the form and fill it out the way you’d want to be able to fill it out if you were arguing you’re not a Washington resident. Because you do not want to be subject to the state’s capital gains tax, say. Or because you do not want your estate or the estate of some family member to be subject to the state’s estate tax. Answering the form’s questions will help you understand the issues. (The form resembles a test where the questions signal the correct answers.)
But let me point to the key bits if you’re thinking about your own Washington state residency.
Primary Residence at Time of Death
The very first question of the affidavit asks for the decedent’s current primary residence, the mailing address, the time living at this location, and then whether there was any known intent to continue or change this residency. So that’s the big thing. And the significance: If you’re going to argue your residence or domicile isn’t in Washington state, you want or need to be able to point to a residence in some other different state. Makes sense, right?
A couple of other questions at the top of the form explore this issue in more detail. The second question, for example, asks if the decedent was residing in a nursing home at the date of death and how long he or she had been in the nursing home. The third question asks if the decedent owned a home and whether that home was or is rented or leased or available for rental or lease. (Obviously, you can’t argue you plan to return to your house in Las Vegas if you’re renting or leasing it to someone else.)
Washington State Real and Personal Property
Next point: A number of the Affidavit’s questions (specifically, questions 3, 4, 6, 8 and 13) ask about whether the decedent owned property in Washington state. Real property (like a home), personal property including cars, business interests and so on. The affidavit also asks about safe deposit boxes in Washington state. Those of course might store of the most valuable personal property a person owns like jewelry and gold. (The form doesn’t ask if you’ve rented storage units or lockers in Washington state. But those should probably be considered in the same manner as safe deposit boxes.)
Pretty obviously if you want to strongly claim another state for your residency or domicile, property located in Washington state matters. A lot.
Also this comment and reminder: If you have any real property located in or personal property stored in Washington state, your estate needs to file a Washington state estate tax return if the estate crosses the filing threshold.
Example: A decedent domiciled in Nevada dies during the last half of 2025 when the filing threshold equals $3,000,000. The total estate includes only two items: A $3,000,000 IRA and then also a small undeveloped parcel located in Kitsap County worth $100,000. The Nevadan’s estate needs to file a Washington state estate tax return because the gross estate value exceeds $3,000,000. Note that the estate will pay only a tiny amount of tax. (About $300 in this situation.)
Washington State Activity Within Prior Five Years
The affidavit also asks questions about any in-state business or personal activities within the last five years. The fifth question for example asks whether the decedent was employed in Washington state any time in the prior five years. The sixth question asks if the decedent owned or operated a business in Washington state during the prior five years. The twelfth question asks about memberships in Washington state community or religious organizations, clubs or societies in the last five years. The fourteenth question asks for a complete list of trips (including location visited, travel dates, and reasons for travel) during the prior five years.
You can see what the Department of Revenue is trying to glean here: How connected are you to Washington state? Close, tight connections weaken an argument that you’re domiciled in some other state. And the lookback period? The prior five years.
Official Government Documentation Connected to Location
A final observation about the affidavit—which works as a good reminder too. The affidavit asks a number of questions that can be easily verified by looking at a government document. For example, the seventh question asks which IRS service center the decedent used to file tax returns. And for the address shown on the federal tax return.
The nineth question asks where the decedent was or is registered to vote.
The tenth question asks if the decedent held a driver’s license and if so from which state.
The eleventh question asks whether the decedent held any licenses or permits at the time of death. These might be recreational permits (fishing or hunting licenses) or professional licenses (like a CPA license or state bar membership).
Finally, the fifteenth question asks if the decedent declared a state of residence near the time of death. If so, it asks to whom the declaration was made and when.
The obvious observations here: All the federal and state government documents you file should match the story of your residency. The tax returns you file, for example, should logically match the residency or domicile you’re claiming. And if you’re domiciled in, say, Texas, the majority or maybe even all your licenses and permits should match that state.
Wrapping Up Comments
Form 85-0045 seems insightful to me if you’re starting to think about residency and domicile and maybe moving to some new state. You get a good picture of the changes to make if you did decide to move.
And just to summarize all this, you ideally want to avoid having any property in Washington state—at least if you’re worried about filing an estate tax return. That property—even if only miniscule—triggers a requirement to file an estate tax return if you’re over the reporting threshold. Reporting obviously puts you on the Department of Revenue radar screen whether you deserve to be or not.
You need a home someplace else. And with that, a mailing address along with things like a drivers’ license, voter registration, and then state and local licenses and permits as appropriate for a resident. Ideally, your profile would resemble a local Floridian, Texan or Nevadan if you decide to reside in Florida, Texas or Nevada.
Do make strong connections to your new location. And then limit or intentionally weaken connections your former state of residence.
Finally, think about how much time you spend you spend in Washington state. Less is better. You may even want to document how little time and how inconsequential the in-state activities.