Guides & how-tos

Tax residency, day counting, and the rules that catch people out.

Clear, practical guides to the day-count rules that decide where you owe tax - and exactly how to track each one automatically with Tax Residency Tracker on iPhone.

Global Rules The 183-Day Rule Explained (and How to Track It) What the 183-day rule really means, how countries count the days, the traps that catch travellers out, and how to track every 183-day threshold automatically on your iPhone. 8 min read Global Rules Schengen 90/180 Rule: How the Calculator Works How the Schengen 90/180-day rule really works - the rolling 180-day window, how days are counted, what the EES border system now tracks, what happens if you overstay, and how to track your remaining days automatically on iPhone. 8 min read US Residency Substantial Presence Test Calculator: US Tax Residency Explained How the IRS Substantial Presence Test works - the weighted 3-year day count, the 31-day and 183-day thresholds, exempt individuals and exceptions, and how to calculate it automatically on iPhone. 8 min read US Residency How to Track US State Residency for Taxes How US state residency really works - statutory residency vs domicile, the 183-day day count, why the burden of proof is on you, and how to track your days by state automatically on iPhone. 8 min read US Residency The California 183-Day Rule and Residency, Explained Does California have a 183-day rule? How California residency really works - the facts-and-circumstances test, the nine-month presumption, the narrow six-month presumption, the 546-day safe harbor, and how to document your days on iPhone. 7 min read US Residency New York's 183-Day Rule and Statutory Residency How New York's 183-day statutory-residency rule works - the 184-day line, the permanent-place-of-abode test, how any part of a day counts, and how to keep audit-proof records on iPhone. 7 min read Country Guides UK Statutory Residence Test: How Many Days Can You Stay? How the UK Statutory Residence Test decides your tax residence - the automatic overseas and UK tests, the sufficient-ties test, how days are counted at midnight, and how to track UK days on iPhone. 8 min read Global Rules How to Count Days for Tax Residency (Every Method) The four ways tax rules count a day - calendar day, the midnight rule, full 24-hour days, and overnight stays - how transit and same-day border crossings work, and how to count them right on iPhone. 7 min read Global Rules How Many Days Can You Stay Without Becoming a Tax Resident? The real answer to how many days you can spend in a country without becoming tax resident - the 183-day default, the ties and rolling-window traps that lower it, and how to track your safe margin on iPhone. 7 min read Digital Nomads Digital Nomad Tax Residency: A Practical Guide Where do digital nomads actually pay tax? How the 183-day rule, Schengen 90/180, ties and the resident-nowhere myth apply to nomads in 2026 - and how to track every country and threshold automatically on iPhone. 8 min read Digital Nomads How to Prove Your Days in a Residency Audit In a residency audit the burden of proof is on you, and undocumented days are counted against you. What evidence proves where you were, and how to keep an audit-ready day log and documents on iPhone. 7 min read Digital Nomads The Best Way to Track Your Days in a Country for Taxes Spreadsheets, calendars, or a dedicated app? What to look for in a tool that tracks your days in a country for taxes - automatic detection, every residency rule, exports and privacy - and how Tax Residency Tracker measures up. 7 min read Country Guides Spain's 183-Day Rule and Tax Residency, Explained How Spain's 183-day rule works: the calendar-year count, temporary absences, the centre-of-economic-interests test, the family presumption, and tracking your days on iPhone. 8 min read Country Guides Portugal Tax Residency: The 183-Day Rule After NHR When you become a Portuguese tax resident: the 183-day rule over any rolling 12 months, the habitual-home test, and what NHR ending (and IFICI/NHR 2.0) means in 2026. 9 min read Country Guides UAE & Dubai Tax Residency: The 183-Day and 90-Day Rules How to become a UAE tax resident in 2026: the 183-day rolling rule, the 90-day route for HNWIs, the centre-of-interests test, and why a treaty TRC still needs 183 days. 9 min read Country Guides The Cyprus 60-Day Rule and Non-Dom Status, Explained How to become a Cyprus tax resident on just 60 days: the four conditions, the 183-day alternative, non-dom benefits, and the 2026 change that dropped the 'resident elsewhere' bar. 9 min read Country Guides Thailand's 180-Day Rule and Foreign-Income Remittance Tax When 180 days in Thailand makes you a tax resident, how the 2024 foreign-income remittance rule works, the pending 2026 changes, and how to prove your day count. 8 min read Global Rules Domicile vs Residence: What's the Difference for Tax? Domicile and tax residence are not the same thing. Learn how they differ, why domicile is 'sticky,' how each is decided, and why dated day records matter for both. 9 min read Global Rules Tax Treaty Tie-Breaker Rules and Centre of Vital Interests Resident in two countries at once? Learn how double-tax-treaty tie-breaker rules decide: permanent home, centre of vital interests, habitual abode, nationality, then mutual agreement. 9 min read Digital Nomads Get Warned Before You Cross a Tax-Residency Threshold Don't find out you're tax resident after the fact. Set threshold alerts for the 183-day rule, Schengen 90/180, the US Substantial Presence Test and US states on iPhone. 8 min read Digital Nomads Changing Your Tax Residency: A Guide for Snowbirds and Movers Moving states or countries mid-year, or splitting time as a snowbird? How to count days on both sides, prove the switch date, and avoid dual residency. 9 min read