The source tax in Switzerland: what your payroll does not explain to you

If you have a B or L permit and work in Switzerland, you have probably never filed a tax return. It's not that you're exempt: it's that your employer withholds the tax directly from your paycheck each month. This is called a source tax, Quellensteuer in German, impôt à la source in French. The system is apparently convenient, but it hides nuances that can cost you hundreds or even thousands of francs if you do not know the rights that apply to you. The tax is calculated using fixed scales, published annually by the Federal Tax Administration and completed by each canton. The 2026 scales are now available and accessible on the AFC site (estv.admin.ch). The percentage applied depends on your family situation: single without children, married with a single salary at home, married with two salaries, with dependent children, etc. The underlying problem is that these scales are standard estimates. They do not take into account real deductions such as extraordinary professional expenses, contributions to the third pillar (3a), donations, mortgage debts or other expenses that a resident with a C permit or with Swiss nationality would normally declare. Here comes the right that many ignore: the request for subsequent ordinary pricing (in French taxation ordinaire ultérieure, abbreviated TOU). If your gross income exceeded CHF 120,000 per year in 2025, you are required to file an ordinary return, whether you like it or not. But if you do not reach that figure and you have significant deductions that the scale does not include, you can voluntarily request a TOU before March 31 of the following year. For the 2025 tax year, that deadline was March 31, 2026. If you did not submit it on time, check if your canton offers an extension: some grant it until the end of April upon express request. The procedure is not particularly complicated but it requires organization. The application must be submitted to the cantonal tax administration, accompanied by proof of income and the deductions that are intended to be applied. Once accepted, a final settlement is made that may result in a refund if the scale withheld more, or in an additional payment if it withheld less. For the majority of workers with real deductible expenses, the net result is favorable. Cantonal differences on this point are relevant. The federal threshold of CHF 120,000 applies throughout Switzerland, but TOU application scales and deadlines vary by canton. Geneva, Vaud and Zurich have procedures with their own particularities. If you have questions about your specific situation, your canton's tax administration is the first point of contact, and staff are used to dealing with foreign workers. ---