Taxed at source: when you must file a Swiss tax return (canton thresholds 2026)

Tax at source is final, until it is not

On a B permit, your employer deducts tax from your salary every month. For many people that deduction is the end of the matter: no forms, no assessment, no refund. Swiss law keeps that simplification only as long as your situation is simple. Three things end it:

• your gross salary reaches CHF 120,000 in a tax year,
• your assets or your income not taxed at source reach the threshold of your canton,
• you ask for a tax return yourself, because the ordinary assessment would suit you better.

In all three cases the procedure is called the subsequent ordinary assessment (nachträgliche ordentliche Veranlagung, NOV). You file a normal Swiss tax return, the tax office calculates your tax with the rate of your municipality and your actual deductions, and the tax at source already deducted is credited. The first trigger is the same everywhere. The second one differs a lot from canton to canton, and that is where most people get caught. This guide shows the rules for the tax year 2026, as at October 2026.

The CHF 120,000 rule

The salary line comes from federal law and applies in every canton. What counts is your gross salary from employment in one tax year, and the line is reached at CHF 120,000 or more, not only above it. A bonus counts as part of that salary.

Two details matter in practice:

• Moving in or out during the year. If you arrived in Switzerland or left during the year, your regular monthly salary is scaled up to twelve months for this test. If you lived here all year and simply started a new job in July, there is no scaling: only what you actually earned counts.
• Married couples. The two salaries are not added together. It is enough if one of you reaches CHF 120,000. You are then both assessed together, including the spouse who earns less.

You do not need to apply. The tax office starts the ordinary assessment on its own and sends you the forms. From then on, you file every year until tax at source ends for you, even if your salary later drops below the line.

Assets and extra income: the canton thresholds 2026

Below CHF 120,000, federal law makes a tax return mandatory if you have assets that are taxable under cantonal law, or income that is not taxed at source. Typical examples of such income are dividends, interest, rent and freelance work. The amounts are set by each canton.

Every canton we checked measures your taxable net assets. Debts such as a loan reduce the figure. Bank accounts and securities abroad count in full. Whether property abroad counts depends on the canton: Zurich leaves it out, while Bern requires a tax return if you own property abroad with an official value of CHF 300,000 or more.

Some cantons go one step further and only count what remains after their wealth tax allowance. That is why the same portfolio can be far above the line in Zurich and far below it in Zug.

Thresholds for the tax year 2026, taken from the cantonal tax administrations and checked in October 2026. The Zug row follows the Zug overview of the subsequent ordinary assessment, 2026 edition, footnote 1. The Aargau row follows the page «Quellensteuern abwickeln» of the cantonal tax office, retrieved on 17 October 2026.

How it works in your canton, with sources, the form and an example: Zurich · Zug · Schwyz · Basel-Stadt · Basel-Landschaft · Aargau · St. Gallen · Thurgau · Geneva.

Some cantons in the table work differently:

• Aargau: As long as your securities do not exceed the wealth tax allowance, the canton charges a flat 15 percent tax on your securities income. You can ask for a tax return instead (withholding tax ordinance, § 9 para. 2).
• Basel-Landschaft: The canton only names an amount for securities income: above CHF 1,700 (withholding tax guide valid from 1 January 2026, section 2.5).
• St. Gallen and Thurgau: These cantons publish no amounts at all.
• Other cantons: They only say that assets or income not taxed at source lead to a tax return.

Whether that applies to you has to be checked individually.

If you cross one of these lines, there is a step many people miss: you have to ask your tax office for the tax return forms by 31 March of the following year. The office will not necessarily know about your portfolio on its own. For the tax year 2026 that means by 31 March 2027.

Example: same portfolio, two cantons

Priya is single, works in Schwyz and earns a gross salary of CHF 98,000. She holds ETFs worth CHF 120,000 and CHF 40,000 in a savings account, with no debts. Her interest and dividends come to CHF 1,400 in 2026.

• In Schwyz: her CHF 1,400 of income is below CHF 2,000. For assets, Schwyz measures «net assets minus social deductions» (withholding tax guide as of 1 January 2026, chapter VII section 2). Whether her CHF 160,000 is still above CHF 50,000 after that is checked case by case; the B permit calculator shows «Individual clarification needed».
• In Zurich: the same CHF 160,000 is well above CHF 80,000. Priya would have to request the forms by 31 March 2027 and file a tax return for 2026.

The salary, the portfolio and the permit are identical. Only the canton decides.

Choosing a tax return voluntarily

If no threshold applies, you can still apply for the ordinary assessment. There are no conditions. It tends to pay off in two situations: you live in a municipality with a lower tax rate than the cantonal average built into the tariff, or you have deductions the monthly deduction ignores. Those include pillar 3a contributions, pension fund buy ins, childcare, debt interest and professional expenses above the flat amount. Pillar 3a is the classic case, and FIN explains the numbers in its article on pillar 3a with a B permit.

Three rules apply to the voluntary route:

• Deadline 31 March. The application for the tax year 2026 must reach the tax office by 31 March 2027. This deadline cannot be extended.
• No way back. Once you apply, you file every year until tax at source ends for you. The application cannot be withdrawn, and the result can be higher than tax at source in a later year.
• Leaving Switzerland. If you move abroad, the deadline ends on the day you deregister.

The filing deadline for the tax return itself is a different matter and can usually be extended. Our overview of tax return deadlines and extensions by canton shows how each canton handles it.

Recalculation or ordinary assessment?

Many people confuse two procedures. A recalculation of tax at source (Neuberechnung der Quellensteuer) corrects mistakes in the deduction itself: a wrong gross salary, a wrong tariff code, or a wrong rate determining income. You request it by the same 31 March. It does not open the door to any additional deductions, and the tax office may decide to run a full ordinary assessment instead.

Some cantons still use the older word Tarifkorrektur. In Lucerne it even means the request for an ordinary assessment, with the lock in described above. Before you sign a form, check which of the two it is.

Withholding tax on dividends: only through the ordinary assessment

Swiss dividends and most Swiss interest are paid out after a 35 percent withholding tax (Verrechnungssteuer). People who file a tax return reclaim it through their securities statement. If you are taxed at source, the refund generally runs through the subsequent ordinary assessment. Without it, the money usually stays with the federal government. In Aargau, where the flat 15 percent tax replaces the assessment for smaller portfolios, you can ask for a full tax return if you want the 35 percent back.

Example: a couple in Geneva

Luca and Mia are married and live in Geneva. Luca earns CHF 110,000 gross, Mia CHF 52,000. Because the salaries are not added together, neither reaches CHF 120,000. Their Swiss shares pay CHF 3,400 of dividends in 2026, from which CHF 1,190 of withholding tax was deducted.

The dividends are income not taxed at source and reach the Geneva line of CHF 3,000. The ordinary assessment is therefore mandatory for both of them. The upside: in that assessment the CHF 1,190 can be credited or refunded, and their deductions count as well.

From B to C permit

With a C permit you are taxed like a Swiss resident. Tax at source stops from the month after the permit is granted. You are assessed under the ordinary rules for the entire tax year, and the tax at source already deducted is credited without interest. From then on you receive provisional tax bills instead of a monthly deduction, so it helps to set money aside.

The same applies if you marry someone with a C permit or a Swiss passport who lives in Switzerland: from the month after the wedding, no tax at source is deducted and you both file a tax return every year. The wider background is in FIN's guide on tax at source versus a tax return.

What if you should have filed and did not?

Missing a mandatory tax return is not a formality. The tax office can charge back taxes with interest for the years concerned, impose a fine for breaching procedural duties, and estimate your income and assets itself if you do not respond to reminders. If you suspect that one of the thresholds applied to you in past years, it is better to raise it yourself than to wait for the office to notice.

If you want a quick first indication for your own case, the calculator on our page about the tax return with a B permit asks for your canton, civil status, salary and assets.

Every case is different, the check is not

Whether you have to file depends on your canton, your civil status, your salary, your net assets and the type of income you receive. This article sets out the rules for the tax year 2026 and two simplified examples; it does not replace individual advice. The legal basis is Article 89 and 89a of the Federal Direct Tax Act (Fedlex) and the Federal Tax Administration circular on tax at source. The cantonal amounts come from the official sources, for example the Zurich information sheet, the Zug overview of the subsequent ordinary assessment 2026, the Schwyz guide on tax at source 2026 and the Geneva directives 2026.

What does generalise: the check takes ten minutes once a year, ideally when your year end bank statements arrive. Put 31 March in your calendar, both for requesting the forms and for a voluntary application.

Related FIN services

• How it works, the form and the deadline per canton: Zurich · Zug · Schwyz · Basel-Stadt · Basel-Landschaft · Aargau · St. Gallen · Thurgau · Geneva
• Tax Return Switzerland
• B-Permit Tax Return
• Swiss Tax Calculator
• Wrong tariff code on your payslip
• Child allowance in tax at source by canton
• Tax return deadlines 2026 by canton