TaxTide counts the days your income depends on — UK Seafarers' Earnings Deduction, 183-day residency counters, and the US presence tests — entirely on your device.
Email a.oh9008@gmail.com — replies usually within a couple of days (sometimes longer when offshore, which feels appropriate).
For UK rules, a day belongs where you were at midnight at the end of it — HMRC's own basis. The US Substantial Presence Test counts any day you touched the US, so record any day you set foot there as a US day. Each rule card explains its own basis in the app.
Two limits apply: no single return visit longer than 183 consecutive days, and your total UK days must never exceed half the days since the period began. Open the rule card and tap it — the step-by-step calculation shows exactly which checkpoint failed.
Days you haven't recorded yet. For SED they are conservatively counted as UK days until you classify them — so fill your timeline for accurate numbers.
TaxTide is offline-first and keeps everything on your device — it is included in your normal iPhone backup (iCloud or computer). There is no TaxTide account or cloud.
Subscriptions are managed by Apple: Settings → your name → Subscriptions → TaxTide Pro → Cancel. The lifetime purchase is a one-time payment with nothing to cancel. Restore a previous purchase from the paywall's "Restore purchases" button.
No. TaxTide provides informational day-count calculations only. Rules change and individual circumstances vary — confirm your position with a qualified adviser before filing.