Live from anywhere. Track everywhere.
Digital nomads live in the gap between residency rules — and the gap is closing. Tax Days tracks Schengen 90/180, 183-day rules in 30+ countries, the US Substantial Presence Test, and the UK SRT on your iPhone. Add a trip in 5 seconds; every applicable rule updates in real time.
What you're up against
Schengen 90/180 is a rolling window, not a fixed year
Most apps treat Schengen as 'days this year.' It's not — it's a rolling 180-day window that moves with you every day. Get it wrong and you're an overstay.
Multiple countries can claim you simultaneously
Spend 5 months in Portugal, 4 in Spain, 3 in Mexico — and any one of them might claim you as a tax resident if you set up a habitual residence.
Tax residency ≠ visa status
You can be in compliance with every immigration rule and still trigger accidental tax residency. The two systems use different definitions and different thresholds.
Reconstruction won't survive an audit
When a tax authority asks where you were on March 14th, 'Probably Berlin?' isn't an answer. They want a contemporaneous record.
What Tax Days does for you
Tracks Schengen 90/180 with a true rolling-window calculation, projects your exhaustion date and earliest re-entry.
Tracks 80+ residency rules across 315 jurisdictions — every country you visit, every state you stop in, all in one app.
Runs the US Substantial Presence Test (3-year weighted) and the UK Statutory Residence Test in real time.
Notifies you 30, 14, 7, 3, and 1 days before you'd cross any threshold — so you can leave with margin.
Exports an audit-ready PDF per jurisdiction, with day count, trip log, and rule evaluations.
Stays on your iPhone. No servers, no accounts, no logs. Optional iCloud sync via Apple's encrypted CloudKit.
The rules you actually need to track
Schengen 90/180
Non-EU citizens can spend at most 90 days in any 180-day period. Rolling, not annual.
Read the guide →183-day rules across 30+ countries
Most countries trigger residency at 183 days. Each defines a 'day' differently.
Read the guide →Portugal NHR / IFICI
Portugal closed NHR to new applicants but the IFICI successor and habitual residence rule still matter.
Read the guide →UAE 90/183-day residency
0% personal income tax, but you need to qualify as a tax resident under the 90 or 183-day tests.
Read the guide →US Substantial Presence Test
If you visit the US, the 3-year weighted formula can trigger US tax residency on worldwide income.
Read the guide →UK Statutory Residence Test
Day-and-tie test on the UK tax year (6 April – 5 April). Catches Americans and EU citizens visiting frequently.
Read the guide →
Free guides and tools
- Calculator
Free Schengen 90/180 calculator
Add your Schengen trips, see days used, days remaining, and the date you'd hit 90 if you stay.
- Calculator
Free 183-day rule calculator
Generic calculator for any country or US state with a day-count threshold.
- Guide
Digital nomad tax guide
The full playbook — picking a tax home, treaty tie-breakers, and the rules that catch you.
- Guide
Expat day counter guide
If you're an American or Brit abroad — FEIE 330-day rule, treaty tie-breakers, and the day-count discipline.
Built for life on the move
Tax Days is the residency tracker that fits a nomad's life — international from day one, privacy-first, and $19.99/year.
