Taxed at source in Switzerland? When filing a tax return gets money back (2026)

Updated on 12.07.2026

If you work in Switzerland on a B permit and your tax is deducted straight from your salary, you may be leaving money with the canton without knowing it. Tax at source (Quellensteuer) uses a flat schedule that bakes in only standard deductions. If your real deductions are larger, such as pillar 3a, a pension-fund buy-in or a long commute, you can often get part of the withheld tax back by filing an ordinary tax return. You do this by requesting a subsequent ordinary assessment (nachträgliche ordentliche Veranlagung, NOV) by 31 March of the year after the tax year. Above about CHF 120'000 gross a year you must file anyway. Below that it is your choice, and this article explains when that choice pays off, and one common belief about starting mid-year that is usually wrong.

How does being taxed at source actually work?

If you are a foreign national living in Switzerland without a C permit, your employer usually deducts tax directly from each pay slip and sends it to the tax office. You never file anything. It feels effortless, and for many people it is roughly right.

Here is the catch. Think of tax at source as a set menu priced for the average diner. It builds in standard, lump-sum deductions that fit most people: a flat amount for work expenses, for insurance premiums, for children. Filing an ordinary tax return is ordering the same meal a la carte: you pay for exactly your situation, no more and no less.

For most people with a very standard situation, the set menu is close enough. But if your real, provable deductions are bigger than the averages baked into the tariff, a la carte is cheaper, and the difference is money that can come back to you.

Do you have to file? The CHF 120'000 line

There are two separate cases, and confusing them is where the money gets lost.

• Gross employment income above roughly CHF 120'000 a year: you are required to file an ordinary tax return (an obligatory NOV). This is not optional, and it cuts both ways. You might get money back, or you might owe more.
• Gross income at or below about CHF 120'000: you do not have to do anything. But you may request an ordinary assessment voluntarily, and this is where most refunds for employees sit (source: ESTV and the cantonal tax offices for Zurich and Aargau).

The deadline for the voluntary request is firm: 31 March of the year following the tax year, and it cannot be extended. For the 2026 tax year, that means 31 March 2027. Miss it, and the source tax deduction becomes final for that year.

Worth checking: the CHF 120'000 figure and the deadline are guide values for the 2026 tax year and are administered by your canton. Confirm the current threshold and the exact procedure with your cantonal tax office before relying on them.

When does filing actually get you money back?

Filing helps when you have deductions the source-tax tariff does not already include. The tariff covers standard lump sums, but it does not know about the things you did with your own money. The usual candidates:

• Pillar 3a contributions, up to the annual maximum (around CHF 7'258 with a pension fund for the 2026 tax year).
• Pension-fund (2nd pillar) buy-ins, which can be sizeable.
• A commute that costs more than the flat allowance, or actual work expenses above the standard amount.
• Childcare costs, further-education costs, debt interest, alimony and donations.

A worked example. Maria is single, employed in Zurich, and taxed at source on a gross salary of CHF 100'000. Over the year the tariff assumes only its standard deductions. But Maria actually paid CHF 7'258 into pillar 3a, which the tariff does not reflect. In an ordinary assessment that CHF 7'258 comes off her taxable income. At a marginal rate of roughly 25 %, that is about CHF 1'800 less tax, refunded to her because it was already withheld. Add a pension-fund buy-in or a long commute and the refund grows.

The direction also depends on where you live. The source-tax rate uses a cantonal average municipal rate, so if your actual municipality is cheaper than that average, an ordinary assessment tends to refund the difference. You can compare municipal tax levels with our tax comparison.

Worth checking: these are guide figures for the 2026 tax year, and the maximum amounts, rates and marginal rates change year to year and by canton. Confirm the current figures for your year before relying on them.

"I started my job in Q4, so I get it all back", right?

This is the belief that is usually wrong, and it matters because it affects exactly the people arriving mid-year. Whether a late start means a big refund depends entirely on why you only had income in the fourth quarter.

The mechanism behind Case B is a rule in Swiss law: for a part-year liability, regularly flowing income such as salary is converted to a full 12 months purely to set the rate (source: DBG Art. 40, and the cantonal guidance in Zurich and Aargau). So if you move to Switzerland in October and earn CHF 8'000 a month, your CHF 24'000 of actual income is taxed at the rate for CHF 96'000. The source tax already used essentially that rate, so filing does not hand back the "missing" nine months. It only helps through deductions the tariff left out.

Case A is different. If you lived in Switzerland the whole year, for example as a student or a non-working partner, and only started earning in October, your rate is set on your genuinely low annual income. Here a large part of what was withheld at the higher monthly rate can come back.

The catch: a voluntary filing is a one-way door

Requesting an ordinary assessment is not a no-risk lottery ticket. In most cantons, once you opt in voluntarily, the decision is binding and applies to the following years too, until you receive a C permit or leave Switzerland. From then on you file an ordinary return every year. In a year where your deductions are smaller, or if you move to a more expensive municipality, an ordinary assessment can mean paying more than the source tax would have taken.

So the honest way to treat it is as a calculation, not a reflex. Work out roughly whether your deductions beat the tariff before you commit. If they clearly do, and your situation is stable, it often pays off. If it is marginal, it deserves a closer look.

What to do before 31 March

If you think an ordinary assessment could work in your favour, a short checklist:

1. Gather your salary statement (Lohnausweis), your pillar 3a certificate, any pension-fund buy-in confirmation, and receipts for commuting, further education, childcare and the like.
2. Estimate whether these deductions are meaningfully larger than the standard lump sums in the tariff.
3. If they are, request the subsequent ordinary assessment from your cantonal tax office in time, by 31 March of the following year.
4. File the ordinary tax return that follows, and let the source tax already paid be credited against it.

Where TaxWize helps

The return you file for an ordinary assessment is a normal Swiss tax return, and that is exactly what TaxWize prepares. It reads your salary statement, your pillar 3a and your other documents, puts each item in the right deduction, and shows whether an ordinary assessment is likely to land below what was withheld, for standard employed situations in Aargau and Zurich. Genuinely cross-border cases, with foreign income or split residence, are still worth taking to a professional. But for a straightforward salary and the usual deductions, the arithmetic that decides whether filing is worth it is exactly the part TaxWize does for you.