How we count

The calculators work from your trips, not from a number you already worked out. That is the point: the mistake usually sits in the count itself. A trip has a first and a last day of presence. From those two dates the code derives the days each rule looks at.

A day is not the same day everywhere

Three things change from one country to the next. What counts as a day: any part of a day in the UAE, the United States, Ireland and Czechia; only being present at the end of the day in the United Kingdom; a day that includes a night there in Portugal. Which period: the calendar year, the UK tax year from 6 April to 5 April, the Australian year from 1 July to 30 June, the Hong Kong year from 1 April to 31 March, or any 12 consecutive months. What the threshold means: "at least 183" and "more than 183" give different answers on day 183. The counter of each country page is set to that country's text, and names it in the result.

A rolling 12-month window is computed in calendar months, so it holds 365 or 366 days depending on the dates, as the UAE decision requires. A day that falls in two trips counts once.

Sources

A country enters the table only once its rule has been opened and read at an official source. 34 countries qualify as of 3 November 2026; 5 others were left out because the official text could not be reached or confirmed, including Italy. For Belgium and the Netherlands, the rule shown rests on the sheet each authority gave the OECD, not on the statute. Those pages say so. A rate appears only if an official scale was read; otherwise the page gives the rule and no rate.

Tests

The counting code has automated tests, using the authorities' own worked examples: HMRC's three deeming examples in RFIG20720, the IRS example of 120 days over three years, and the FTA's examples 12 to 17 on UAE residence. Each threshold is also tested on both sides of the boundary: 15 and 16 days, 45 and 46, 90 and 91, 182 and 183. The US test runs in whole sixths of a day, so no rounding error can move a result at exactly 183.

What the result is not

A threshold reached is arithmetic, not a decision. Tax authorities also look at home, family, work and centre of interests, and a tax treaty can override domestic law. Exceptional days and special statuses are only handled where the calculator asks about them. The calculators do not cover social security, immigration rights or inheritance rules, and the Schengen counter is a visa rule that has nothing to do with tax.

Corrections

Rules are read again at least once a year and when a text changes. Found a mistake? Tell us at the address on the contact page, with the source. We correct it and update the date at the bottom of the page.