Withholding tax in Switzerland: who it applies to and how it works

Withholding tax affects several hundred thousand workers in Switzerland: cross-border commuters, holders of a B or L permit, certain posted workers. Many pay too much tax because they don't know they can request a correction or switch to an ordinary assessment. This guide explains the system and the steps worth taking.

At a glance

Withholding tax is deducted directly from salary by the employer, who then pays it to the tax authority.
It applies mainly to cross-border commuters (G permit), residents with a B or L permit (without a C permit) and certain special cases.
The rate depends on the canton of employment, marital status, number of dependent children and the spouse's income.
If your gross annual income exceeds CHF 120,000, a subsequent ordinary assessment (SOA) applies automatically. Below that threshold, you can request one.

What you need to understand

In Switzerland, a worker's tax status depends on their type of permit and their place of residence:

Swiss citizens and C permit holders declare their taxes by filing an ordinary tax return.
Other foreign residents (B, L, F permits) and cross-border commuters (G permit) are in principle taxed at source on their employment income.

Withholding tax combines all three levels (federal, cantonal, communal) into a single simplified rate, calculated according to your family situation (single, married, with or without children) and your income.

Advantage: no annual paperwork — the tax is deducted automatically each month.

Disadvantage: the rate is flat and does not account for your individual deductions (pillar 3a, above-standard professional expenses, medical costs, etc.). Many people therefore pay more tax than necessary.

Who is affected

Residents in Switzerland

B permit holders without a C permit.
L permit, F permit, N permit holders.
Employed persons only (no withholding tax for the self-employed).
Mixed couples: if one spouse is Swiss or holds a C permit, the entire household is in principle assessed under the ordinary procedure.

Non-residents

Cross-border commuters (G permit): taxed at source in Switzerland, with a specific regime based on the tax treaty of their country of residence (France, Italy, Germany, Austria).
Posted workers temporarily working in Switzerland.
Artists, sportspeople and speakers performing occasionally in Switzerland.

Subsequent ordinary assessment (SOA)

The subsequent ordinary assessment allows you to move from flat-rate taxation to a full tax return, with all standard deductions. It is:

Automatic if your gross annual income exceeds CHF 120,000 (or CHF 50,000 for cross-border commuters in certain cantons).
Optional on request if your income is below the threshold. The request must be filed by 31 March of the following year.

When to request the SOA

You contribute significantly to your pillar 3a.
You have high medical expenses.
You pay alimony.
You make substantial donations.
You have high professional expenses (long commute, continuing education).
You have BVG/LPP buy-ins to declare.

In all these cases, the SOA can mean several hundred to several thousand francs less in tax per year.

Important: a decision with lasting consequences

Once requested, the SOA applies for subsequent years until you leave Switzerland or obtain a C permit.
You will need to file a full tax return every year, with all the obligations that entails.

Correction request (without switching to the SOA)

For incomes below CHF 120,000, if you do not want the full SOA, you can request a targeted correction:

File with your cantonal tax administration by 31 March of the following year.
Attach the supporting documents for the deductions you wish to claim (3a certificate, donations, medical expenses).
You receive a refund if the corrected calculation is in your favour.

Cross-border commuter specifics

Bilateral tax treaties determine who levies the tax:

French cross-border commuters (Geneva): tax is levied in Switzerland, with partial restitution to France under a bilateral agreement.
French cross-border commuters (Vaud, Basel, Berne, Valais, Jura, Neuchâtel, Solothurn): tax is levied in France; a certificate of residence must be provided to the Swiss employer.
Italian cross-border commuters: specific regime still evolving since the 2020 agreement (which entered into force in 2024).
German and Austrian cross-border commuters: separate regimes, shared taxation.

Check your situation with the tax administration of your canton of employment and your national tax authority.

Documents to keep

Annual salary certificates (showing the withholding tax deducted).
Certificate of domicile from your municipality (Switzerland) or country (cross-border commuters).
3a certificate if you contribute (essential for a correction request).
Receipts for unreimbursed medical expenses.
Health insurance policy (LAMal/KVG or the foreign equivalent for cross-border commuters).
Tax assessments received from the tax authority.
Annual withholding tax statement.

Deadlines to keep in mind

31 March: deadline for filing an SOA request or correction for the previous year. Without a request by this date, the withholding tax becomes final.
C permit obtained during the year: automatic switch to the ordinary assessment from the following year.
Change of canton: notify the relevant authority promptly — the withholding tax rate changes from canton to canton.

Common mistakes

Ignoring the correction request. If you contribute to a pillar 3a every year, you are almost certainly paying too much tax without a correction.
Requesting the SOA without thinking it through. Once filed, the SOA applies until you obtain a C permit or leave Switzerland. Consider carefully whether you plan to leave or whether your situation is likely to change.
Forgetting to inform your employer of a marriage, birth or divorce. The rate changes, and you could end up paying too much — or too little.
Assuming your employer's calculation is correct. Employers apply a standard rate. Without a correction, your personal deductions are not taken into account.
Overlooking bilateral tax treaties if you are a cross-border commuter. The regime varies significantly depending on the canton and your country of residence.

Useful official links

ch.ch · Withholding tax
Federal Tax Administration · Withholding tax
Tax administration of your canton of employment (search "withholding tax" + canton name).
Bilateral tax treaties (published by each border canton).

How Admini can help

Withholding tax means a lot of paperwork spread across your employer, your canton of employment, your municipality and sometimes a foreign country. Admini helps you:

Centralise salary certificates, 3a statements, medical receipts and tax assessments in one place.
Prepare a complete correction request every year before 31 March.
Receive a reminder before that deadline so you don't let hundreds of francs slip away.
Keep a clear record of tax assessments and refunds received.

The goal is to recover every year what you are entitled to, without having to dig through your employer's emails to track down your salary certificates.