Multi-Country Tax Residency Day Tracker

Why one trip log, many answers

If you spend a year moving between three or four countries, the question is not "am I tax resident?" but "which of these countries thinks I am?" — and they will each answer using different numbers, over different periods, counted differently. A single log of where you were, evaluated against each country's own rules, is the only way to see all the answers at once.

The three things countries disagree about

1. How many days

183 is the most common threshold, but treating it as universal will catch you out. Switzerland can make you resident after 90 days without gainful activity — and just 30 days if you are working. South Africa uses 91 days as one limb of a five-year test. Thailand uses 180. India and Malaysia use 182. The Netherlands has no mechanical day count at all and decides on facts.

2. Over what period

Most countries use the calendar year, but not all:

• Australia runs 1 July to 30 June.
• India runs 1 April to 31 March.
• United Kingdom runs 6 April to 5 April.
• Brazil, Indonesia, New Zealand, Portugal and Switzerland measure over any rolling 12-month period, so there is no reset date at all.

The rolling-window countries are the ones people misjudge most. With a calendar year you can plan around 1 January. With a rolling window there is nothing to plan around: every day you were present stays counted for a full year.

3. How days are counted

In most countries, any part of a day physically present counts as a whole day, so both your arrival and departure days count. The UK is the significant exception: a day counts only if you are in the UK at midnight, so the day you leave does not count. This tracker applies each convention to the right country rather than assuming one applies everywhere.

A worked example

Suppose that in 2024 you spent 1 January to 1 July in Spain, 2 July to 1 September in Portugal, and 2 September to 15 October in France.

Spain counts 183 days — exactly its threshold, so you are over and very likely Spanish tax resident. France counts 44 days against 183, comfortably under. Portugal also has a 183-day threshold, but measured over a rolling 12 months rather than the calendar year. One trip log, three thresholds, one problem.

Note what the tracker does with dates in the future. A calendar-year or tax-year country counts the whole period, so a trip you have logged for later this year already appears in the total — which is the point, because it lets you see a threshold coming. A rolling-window country is measured over the 12 months ending today, so days you have not yet travelled are not counted; that figure answers "where do I stand right now", and it rises as you actually take the trip. The two columns are asking slightly different questions and it is worth knowing which is which.

Note what happens if you shift the Spanish trip to end on 30 June instead: 182 days, one day under. That single day is the difference between worldwide taxation in Spain and not — which is exactly why people count.

The dangerous assumption

The most common mistake made by people who track days carefully is believing that staying under every threshold makes them tax resident nowhere. It usually does not.

Almost every country has residency tests that do not depend on days. France taxes you as resident if your principal home, main professional activity or centre of economic interests is there. Canada's primary test is residential ties — a home, a spouse, dependants — and the 183-day rule is a backstop, not the main event. Australia's primary test is whether you "reside" there in the ordinary sense. Spain counts sporadic absences towards your 183 days unless you can prove tax residence somewhere else.

In practice, most people who believe they are resident nowhere are still resident in the country they left, because they never established residency elsewhere and never severed the ties that kept them resident at home. A low day count is evidence, not a conclusion.

Being resident in two countries at once

Dual residency is common and not in itself a problem. Domestic residency tests are written without reference to each other, so overlapping is the normal outcome of splitting a year between two places.

Where a double tax treaty exists between the two countries, it contains tie-breaker rules applied in a fixed order: where you have a permanent home available; if both, where your centre of vital interests lies; if that is unclear, where you have an habitual abode; then nationality; and finally agreement between the two tax authorities. The tie-breaker decides which country treats you as resident for treaty purposes — it does not erase the other country's domestic residency, and you may still have filing obligations there.

Without a treaty, there is no tie-breaker. Both countries can tax you as a resident and your only relief is whatever unilateral foreign tax credit each offers. This is the situation worth planning around, and it is why the countries you spend time in matter as much as the number of days.

Practical tracking

Log trips as you take them rather than reconstructing a year in April. Reconstructed counts are reliably wrong at the margins, and the margins are what matter. Keep the evidence — boarding passes, card transactions, phone records — because in a dispute the burden of proving where you were falls on you.

Countries covered

Two entries need their own tools. The United States weights three years of days rather than counting one, and the United Kingdom applies a ties-based analysis below 183 days. This tracker shows your day counts for both and links out for the full tests.

If you are tracking days for immigration rather than tax, the rules are different again — see the Schengen 90/180 calculator for the European short-stay allowance.