If you're leaving Washington for Nevada, and spending part of the year in California, you're going to have to prove where you were. Not roughly. Day by day.
The best time to build that record is while you're living it. A day-tracking app does that for you.
Why Washington day counts now matter
Washington's new income tax, ESSB 6346 (Chapter 238, Laws of 2026), imposes a 9.9% tax beginning January 1, 2028 (§201). Preliminary November 4 election returns show voters rejecting Initiative 645, the repeal effort, 58.12% to 41.88%. A court challenge is still pending. Plan as if the tax is coming. (Here's how the tax works.)
The residency definition is in §101(8), now RCW 82A.04.010(8). You're a Washington resident if either:
- You're domiciled here—unless you (A) kept no permanent place of abode in Washington for the entire year, (B) kept a permanent place of abode outside Washington for the entire year, and (C) spent no more than 30 days in Washington in the aggregate.
- You're not domiciled here, but you kept a place of abode in Washington and were physically present more than 183 days.
Two details matter:
- A "day" means a calendar day or any portion of one (§101(8)(b)). Fly in at 11 p.m.? That counts. Driving through Vancouver to Portland is less clear: the statute doesn't exempt transit, and DOR hasn't said whether passing through is physical presence. Log those trips.
- The 30-day exception is narrow. It only helps someone still domiciled in Washington; the 183-day abode test is for non-domiciliaries. All three conditions must hold for the full year. Keep a Seattle condo, or spend day 31 here, and it's gone.
Staying at or below 183 days doesn't protect someone still domiciled here. Domicile is a separate test. (More on the 183-day rule.)
Washington also has a part-year rule (§101(8)(c)). If you're a resident under either test, you're a resident for the part of the year in which you were domiciled here or maintained a place of abode here. So the timing of your move can matter as much as your annual day count.
What we don't know yet. DOR hasn't issued rules on counting days, acceptable proof, or what "permanent place of abode" means. Don't expect it to be more forgiving than "any portion."
California is the bigger risk
Nevada has no income tax. California does, and the FTB audits residency aggressively.
- Nine-month presumption. Under Rev. & Tax. Code §17016, anyone who spends more than nine months of the taxable year in California is presumed a resident. The presumption is rebuttable. Under nine months does not mean you're safe.
- Resident definition. §17014 covers anyone in California for other than a temporary or transitory purpose, and anyone domiciled in California who is outside the state for a temporary or transitory purpose.
- Closest connections. In Appeal of Bragg (2003-SBE-002), the Board of Equalization listed the factors it weighs: where your homes are and what they cost, where your spouse and kids live, where the kids go to school, where you're registered to vote, your driver's license, car registration, bank accounts, doctors, professional licenses, club memberships, and—yes—days spent in California versus elsewhere. The FTB's Publication 1031 walks through the same analysis.
Days are one factor among many in California, and presence is evidence, not the test. But the FTB can check your days against card and phone records. If your day log conflicts with other contemporaneous records, the discrepancy can undermine the credibility of your residency claim.
Memory loses. Records win.
Residency audits happen years later. Nobody remembers whether they flew home on the 14th or the 15th of March three years ago.
Reconstructing a calendar from card statements after the fact is slow, expensive, full of gaps, and easy for an auditor to attack.
A contemporaneous log is better. An app that records your location in the background gives you a record made at the time, not one built for the audit. Pair it with what you'd have anyway:
- credit card and bank statements
- flight confirmations and boarding passes
- toll, parking, and rideshare records
- phone carrier records
Together they corroborate each other. Alone, each one has holes.
Keep the exports. Don't rely on a vendor still being around in five years.
Choosing an app
Three apps worth looking at. Pricing below is from each vendor's site, checked November 4, 2026. Confirm before you buy.
**Monaeo**. $99/user/month or $999/user/year, with a free trial; enterprise pricing is custom. Automatic day counting, multi-jurisdiction tracking, audit-ready exports. Built for complex individual cases and employers with multistate workforces.
**TaxDay**. $9.99/month after a free trial (30 days per its site; app-store listings differ). iOS and Android. GPS tracking across all 50 states, threshold alerts, travel categories, receipt attachments, and exportable reports.
**Domicile365**. $19.99/month after a 60-day free trial, no credit card required. Background location logging, alerts by country, state, and city, CSV/Excel/PDF logs, advisor access, and a signed PDF report. iOS, macOS, Android, and Windows.
What to look for:
- Does it count any portion of a day as a day? That's Washington's rule.
- Can you export the raw log, not just a summary?
- Can your CPA or lawyer get access?
- Does it handle multiple states at once (WA, CA, NV)?
Before choosing an app, check its privacy policy, data-retention practices, and whether you can export and delete your location history. You're creating a detailed record of where you've been. Make sure you understand who controls it.
Don't assume an app's default count matches Washington law, especially for transit, partial days, and dates with more than one state.
None of these apps decide whether you're a resident. They count days. Domicile is still about where your permanent home really is. Moving your home, changing your license and voter registration, and relocating other important personal connections can help establish that you've genuinely changed domicile. (See Leaving Washington: Domicile, Residency and Tax Planning.)
Which one? For an affordable day counter, TaxDay is cheapest. For frequent interstate travel, prioritize exports and reports; Domicile365's signed PDF is built for that. For complex multistate situations, Monaeo's reporting plus professional help may be worth the price. I haven't tested them and can't say one is best.
Bottom line
If you're changing domicile, start tracking now, not in April. The app costs less than an hour of an accountant rebuilding your calendar.
Nothing in this article is legal or tax advice for your specific situation.
Want to talk through your move? Schedule a 20-minute call.
