Swiss residence by stay, explained

Switzerland’s presence test is short, and that is exactly what makes it easy to trip. Stay in Switzerland for an unbroken run of 90 days without gainful activity and you are treated as resident for tax — and if you are working while there, the qualifying stay is far shorter still, a third of the standard run. Residence can also arise the other way entirely, by taking up residence with the intent to settle, which needs no particular count at all. The mechanic people misjudge is the word “unbroken”: a weekend across the border does not restart anything.

Day counts alone are not determinative here, which is why this rule is advisory in Residay: the run is one input, and the intent-to-settle limb is a facts question no counter reaches.

How days are counted

The evaluator watches for a contiguous stay rather than a yearly total. Any part of a day in Switzerland counts as presence for that day, assessed against the calendar year. Short interruptions are disregarded — leave briefly and the stay is treated as continuing through the gap. Residay stitches the run together across gaps of up to 7 days; that figure is the app’s tracking heuristic for “brief”, not a statutory line, so a gap slightly longer than it should not be read as a legal reset.

The effect is retroactive to the first day of the stay. When a run reaches the threshold, the residence it signals covers the entire stay from its beginning, not merely the tail end — months you may have already treated as a visit.

Lump-sum taxation: the forfait

Switzerland’s expenditure-based regime — imposition d’après la dépense, Besteuerung nach dem Aufwand, colloquially the forfait fiscal or Pauschalbesteuerung — assesses a qualifying foreign national on living expenditure rather than on worldwide income and wealth. It is worth being exact about where it sits relative to everything above: the regime presupposes Swiss tax residence, with unlimited liability. Nobody is taxed on expenditure instead of being resident. They are taxed that way because they have become resident, and that is the question the stay above bears on without settling.

Three conditions do most of the filtering. The regime is closed to Swiss citizens, and where spouses are assessed jointly both must qualify, so a single Swiss passport in a marriage ends the discussion. It is available on taking up Swiss tax residence for the first time, or on returning after a long absence. And it requires that no gainful activity is carried on in Switzerland: employment or self-employment here disqualifies, while managing your own assets, or working abroad for foreign clients, does not. That last condition is the same fact the app already asks you about for the shorter stay threshold, and it does double duty — gainful activity in Switzerland both shortens the run that can make you resident and forecloses the regime you may have wanted residence for.

The base is your worldwide living expenditure, subject to statutory floors. Since the reform in force from 1 January 2016, with transitional protection for pre-existing arrangements running to the end of 2020, the federal minimum base has been CHF 400,000, and the base must in any event be at least seven times the rent or rental value of your home, or three times the annual cost of board and lodging. Cantons set their own minimum at or above the federal floor and levy a deemed wealth tax alongside it, so the figure that governs an assessment is cantonal rather than federal. The amounts are index-linked; confirm the current ones with the canton concerned. A control calculation then ensures the expenditure tax is not lower than ordinary tax on defined Swiss-source income and assets.

The cantonal dimension is not a detail. Several cantons have abolished the regime outright — Zurich first, by popular vote in 2009, followed by Schaffhausen, Appenzell Ausserrhoden, Basel-Landschaft and Basel-Stadt. A federal popular initiative to abolish it nationwide was rejected in November 2014, which left the patchwork in place rather than resolving it. Where you settle therefore decides whether the regime exists at all, and at what minimum, before any question of how long you stayed there.

What Residay computes and what it asks

From the ledger, the app derives the length of your current contiguous run, the interruptions it has absorbed, and the projected date the run would reach the modelled threshold if it continued.

One fact changes the arithmetic entirely, and the ledger cannot see it: whether you are carrying out gainful activity — employment or self-employment — while in Switzerland. Residay asks, because with gainful activity the relevant threshold drops to a third of the standard stay length, and the chart’s line moves accordingly. The answer is attested once per calendar year and dated, so the shorter line is applied exactly when it should be. What no attestation covers is intent to settle: keeping a home and arriving with the intention of staying can make you resident before any run matures, and that assessment belongs with an adviser.

Planning notes

• Treat brief exits as pauses, not resets. If you need a genuine break in the stay, make it unambiguous in length and keep evidence of where you were.
• Remote work counts as work. If you answer email for your employer from a Swiss chalet, the gainful-activity question is live, and the shorter threshold with it.
• The forfait is a cantonal decision as much as a Swiss one. Check that the canton you are considering still offers it, and on what minimum base, before the location is chosen rather than after.
• Retroactivity means exposure crystallises backwards over the whole stay — the time to take advice is before a run gets long, not after.
• The Federal Tax Administration’s guidance, linked above, is the operative reference; professional advice is required before relying on any Swiss position.