Real-time residency dashboard
Every rule on one screen. Traffic-light status. Days used, days remaining, days projected, at a glance.
Now tracking 254 jurisdictions
Never guess how many days you have left.
Log a trip. Tax Days counts it against every residency rule you care about, and warns you before you cross one.
- All 50 US states
- Substantial Presence Test
- Schengen 90/180
- UK SRT
- Jurisdictions
- 254
- Free trial
- 7 days
- Your data
- On-device
Why Tax Days
US + International, in one app
State residency, federal SPT, Schengen 90/180, UK SRT, and more. The first tracker that does both well.
Automatic, not a GPS trail
A few low-power location readings a day become your day counts, or log trips by hand. No continuous GPS, and no trail on anyone's server.
Audit-ready records
Contemporaneous day counts, exportable to PDF and CSV. Defensible if your state ever asks.
FeaturesEvery rule that matters,
Every rule that matters,
in one beautiful app.
A calendar that thinks in trips
Color-coded days, tap-to-add simplicity, and conflicts flagged automatically. Your entire travel year, at a glance.
Schengen 90/180, finally readable
Rolling 180-day window. The exact day you'd hit 90 if you stay. No more spreadsheet math, no more anxious math at the airport.
Smart alerts before you cross
Configurable warnings at 30, 14, 7, 3, and 1 days before any threshold. Set it once. Stop worrying.
Year-over-year stats
Days per jurisdiction, trip insights, year comparisons. Spot patterns before your accountant does.
Private by default
No accounts. Your trips and location history stay on your devices and in your iCloud, never on our servers.
How it worksThree steps from blind
Three steps from blind
to bulletproof.
- 01
Pick your jurisdictions
Choose from 254 states, countries, and tax regions, from New York and California to Schengen, the UK, and the federal Substantial Presence Test.
- 02
Log every trip on a single calendar
Tap any date to add a trip. Color-coded days. Conflicts flagged automatically. Your entire travel year, at a glance.
- 03
Always know where you stand
Real-time dashboard. Smart projections. Notifications at 30, 14, 7, 3, and 1 days before any threshold.
How we know
Every threshold traced to a primary source.
Tax Days is not an opinion about where you live. Each rule it tracks comes from the statute, regulation, or tax authority guidance that defines it, and we link you to the original.
US Substantial Presence Test
The weighted three-year count that decides US tax residency: all of this year's days, a third of last year's, a sixth of the year before. Tax Days runs the same formula the IRS publishes.
IRSSubstantial Presence Test(opens in a new tab)New York statutory residency
Days plus permanent abode, not days alone. New York's own audit guidelines set out how auditors count a day and what counts as an abode, which is why the app tracks both.
NY Dept. of Taxation & FinanceNonresident Audit Guidelines (2021)(opens in a new tab)UK Statutory Residence Test
Automatic tests first, then the sufficient ties test, where the day threshold moves with how many ties you have. Tax Days models the tie count rather than assuming a flat 183 days.
HMRCRDR3: Statutory Residence Test guidance(opens in a new tab)California safe harbor
California treats a long absence under an employment contract differently from an ordinary one. The published FTB guidance is what the app's California rule follows.
California FTBFTB Publication 1031, Guidelines for Determining Resident Status(opens in a new tab)
Whoever you are. Wherever you travel.
Tax Days is built for anyone whose tax situation depends on where they spend their days.
Digital Nomads
Track days across 50+ countries to avoid triggering tax residency where you don't want it.
Save 6-figures in taxRemote Workers
Bouncing between states or countries? Tax Days tracks the day count so you know your state residency stays clean.
State tax complianceExpats & Returners
Coming back to the US? Use Tax Days to track your re-entry days against IRS Substantial Presence Test.
IRS complianceInternational Consultants
Working across borders? Track local presence days for VAT, double taxation treaties, and PE risk.
Multi-jurisdiction
254 jurisdictionsState residency. Federal SPT.
State residency. Federal SPT.
Every 183-day rule.
Tax Days knows the difference between New York's 184-day rule and California's facts-and-circumstances test. Each jurisdiction has its own threshold, its own tax year, and its own definition of a “day”. Tax Days handles them all.
- New York · 184 days
- California · 9-month safe harbor
- Florida · 183-day domicile
- Texas · domicile
- Illinois · 9-month presumption
- New Jersey · 183-day
- Substantial Presence Test
- Schengen Area · 90/180
- United Kingdom · SRT
- Canada · 183-day
- Australia · 183-day
- Germany · 183-day
- France · 183-day
- Spain · 183-day
- Italy · 183-day
- Portugal · NHR
- Netherlands · 183-day
- Switzerland · 90-day
- UAE · 183-day
- Singapore · 183-day
- Japan · 183-day
- Mexico · 183-day
- …and 290 more
ResourcesEverything you need before
Everything you need before
you download the app.
Free tools, in-depth guides, a complete rules reference, and a plain-English glossary. The same content the iPhone app runs on, opened up on the web.
- Free calculators
Run the math now.
Schengen 90/180, IRS Substantial Presence Test, and a generic 183-day calculator. Browser-based, privacy-first.
Open the tools → - 254 jurisdictions
Browse every rule.
All 50 US states, 200+ countries, and the Schengen Area, searchable, filterable, with thresholds and links to in-depth guides.
Browse rules → - 144 guides
Read the playbooks.
Plain-English guides on the 183-day rule, NY 184-day rule, Schengen 90/180, snowbird domicile, and 47 more topics.
Read the blog → - 33 terms
Definitions you can act on.
Plain-English definitions of every term you'll see in this space, from abode and domicile to FEIE, SRT, casa habitación, and Wohnsitz.
Open the glossary →
Why Tax DaysCounting days
Counting days
shouldn't cost
you five figures.
Every other tracker is either too clunky to use, too expensive to justify, or too narrow to cover the way people actually travel. Tax Days is what every accountant has been waiting for their clients to download.
A single missed day costs more than a decade of Tax Days.
New York runs one of the most aggressive residency audit programs in the country, and one state filing mistake can cost five figures. Tax Days is $29.99 a year, about the price of two coffees a month.
US states *and* the world, in one app.
Most trackers pick a lane: US states, or Schengen, or enterprise mobility. Tax Days covers all of it in one beautifully designed app, on the device you actually carry.
Low-power by design. Battery and privacy intact.
Continuous GPS trackers drain your battery and keep your location trail on their servers. Tax Days takes a few low-power readings a day, keeps them on your devices, and lets you confirm or log trips yourself, the same way your CPA counts them.
Built with privacy first
Your travel days are private and never reach our servers.
Your data is yours
Your trips and location history live on your iPhone and sync through your own iCloud. They never reach our servers, and we can't see them.
iCloud sync
Syncing is handled by Apple's CloudKit, in a private iCloud database that we have no access to.
Offline by design
Track days from a plane, a remote village, or any location. No internet needed.
No ads, no data sales
We never receive your location, we show no ads, and we don't sell data. Tax Days respects your privacy.
PricingOne hour with a tax attorney
One hour with a tax attorney
costs $300+. Tax Days is $49.99/yr.
A single state filing mistake can cost thousands. Tax Days is cheaper than the consultation you'd need to fix it.
| Feature | Tax Days | TaxBird | Domicile365 | Monaeo |
|---|---|---|---|---|
| Annual price | $29.99 | $39.99 | ~$220 | $999 |
| Low-power location (no continuous GPS) | ✓ | – | – | – |
| US state rules | ✓ | ✓ | ✓ | ✓ |
| International rules | ✓ | – | ✓ | ✓ |
| Schengen 90/180 | ✓ | – | ✓ | ✓ |
| Smart projections | ✓ | ✓ | – | – |
| iCloud sync | ✓ | – | – | – |
| Audit-ready PDF/CSV export | ✓ | ✓ | ✓ | ✓ |
Competitor prices are compared in US dollars. Your own price is shown below in your local currency.
See the full comparison, including Topia and iReside →
Free
$0
Automatic tracking for the jurisdictions you pick at setup. Good for one home state or a simple travel year.
- Automatic day counting for every place you pick at setup
- Threshold alerts, projections, and the last 30 days of your timeline
- 5 hand-logged trips a year, on-device storage, and iCloud sync
Pro
$49.99/yr
Just $4.17/month, billed yearly
- Add any of 250+ jurisdictions and custom rules at any time
- Unlimited trips, plus recurring trips from templates
- Your full timeline history, not just the last 30 days
- Audit-ready PDF and CSV export of your tax summary
- Everything in Free, including alerts at 30, 14, 7, 3, and 1 days
Enterprise
Custom
For firms and employers whose people each need their own day record.
- Each person tracks their own days in the app
- PDF and CSV exports to share with your compliance team
- Pricing for groups on request
- Onboarding help and priority support
Prices are set by the App Store. Apple periodically adjusts them as currency exchange rates move, so your exact price is always confirmed by the App Store before you subscribe.
Tax residency updates, in your inbox
Occasional updates on IRS and country tax-rule changes, new calculators, and app features. No spam, unsubscribe anytime.
Questions
What people ask
How is Tax Days different from TaxBird, Domicile365, or Monaeo?
Tax Days combines US state, US federal, and international tax residency rules in one app, at $29.99/year. It can track automatically with low-power location or let you log trips by hand, and your travel history never reaches our servers. TaxBird doesn't run named Schengen or UK SRT tests, Domicile365 and Monaeo cost considerably more, and our comparison pages go through each one feature by feature.
What's the 183-day rule, exactly?
Most jurisdictions consider you a tax resident if you spend more than 183 days in a calendar (or tax) year there. The exact threshold and how a 'day' is counted vary, New York counts any part of a day, Schengen uses a rolling 180-day window, and the federal Substantial Presence Test uses a 3-year weighted formula. Tax Days handles all of these.
Does Tax Days track me with GPS?
Not continuously. If you allow location access, Tax Days uses the iPhone's significant-location-change monitoring, which records a few low-precision readings a day instead of a continuous GPS trail, and turns them into day counts. It's included free. You can also skip location entirely and log arrivals and departures by hand.
What jurisdictions does Tax Days support?
254 jurisdictions including US states (NY's 184-day + abode rule, CA's 9-month safe harbor, FL, TX, IL, NJ, and more), the federal Substantial Presence Test, Schengen 90/180, the UK Statutory Residence Test, and a configurable 183-day rule for any country.
Is Tax Days suitable for an audit?
Yes. Tax Days produces contemporaneous, exportable records (PDF and CSV) showing your trips and day counts. These are the kind of records tax authorities expect to see in a residency audit. Tax Days is not legal or tax advice, but it gives your CPA exactly what they need.
Will my data sync across my devices?
Yes, through your own iCloud account. Your trips and location history are stored on your iPhone and synced through iCloud, where we can't see them. They never reach our servers, and there's no account to create.
How much does Tax Days cost?
Tax Days Pro is $49.99/year (with a 7-day free trial) or $7.99/month. There's also a free tier: automatic tracking and alerts for the jurisdictions you pick at setup, 5 hand-logged trips a year, and the last 30 days of your timeline.
Is Tax Days iOS only?
Yes. Tax Days is a native iPhone app for iOS 17 and later. It can run on an iPad as an iPhone app, but there is no iPad or Mac version.
Who is Tax Days for?
Snowbirds splitting time between New York and Florida. Remote workers hopping between states. International travelers tracking the Substantial Presence Test. Digital nomads watching their Schengen days. Expats. Anyone whose accountant said "you need to start tracking your days."
Ready to countYour days count.
Now you can count them back.
Stop doing tax math on napkins, in spreadsheets, or worse, in your head. Tax Days does it the moment you log a trip, and warns you before any of it costs you money.
Every rule that matters
254 jurisdictions, including all US states, the SPT, Schengen, UK SRT, and more.
Real-time status
Traffic-light dashboard. Smart projections. Notifications before you cross.
Audit-ready
Contemporaneous records, exportable to PDF and CSV. Defensible if asked.
$49.99 a year
Less than the consultation you'd need to fix a single missed day.
7-day free trial · iPhone · Your data stays yours