Withholding tax at source: rates and reassessment

In Switzerland, many workers do not settle their taxes through the annual return but instead have them withheld directly from their salary, month after month. This is withholding tax at source (Quellensteuer): the employer acts as a substitute, calculates the deduction according to a tariff and pays it over to the tax authority. The mechanism makes life easier for the taxpayer, but it conceals several pitfalls: rates to be read correctly, possible corrections and thresholds that bring you back into ordinary taxation.

Who is liable to withholding at source

Withholding tax at source applies above all to:

Foreign workers without a C settlement permit resident in Switzerland (typically holders of a B, L or F permit).
Cross-border commuters and residents abroad who work in Switzerland.
Certain specific categories (directors resident abroad, artists, sportspeople, speakers, recipients of pension benefits abroad).

Those with a C permit, a spouse with a C permit or Swiss nationality are instead taxed under the ordinary procedure. The employer must check the employee’s status on hiring and update it when it changes.

How the rates work

The deduction is not a fixed percentage: it depends on a tariff that takes account of the personal situation. The letters identify the main categories:

A: single person without children.
B: married with a single income.
C: married with a double income.
H: single person with dependent children.

To these are added further letters for special cases and an indication of whether the church tax contribution is included. The tariff already incorporates an estimate of the ordinary deductions (professional expenses, insurance premiums, family charges), so that the rate applied varies according to income and children. The tables are cantonal: the same salary produces different deductions depending on the canton of liability, which as a rule is the canton of residence (or, for non-residents, the canton where the employer is based).

The month-by-month calculation

The employer applies the tariff to the gross salary for the period, normally including the thirteenth month’s pay, bonuses and fringe benefits. Watch the determining income: to establish the rate, the whole of the benefits is generally taken into account, and in the case of multiple employment relationships or part-time activities a global rate calculation is triggered to prevent the splitting from artificially lowering the rate. Typical errors are using the wrong letter after a marriage or a birth and failing to report a second job.

Reassessment and corrections

If errors emerge during the year (an incorrect tariff, changed family circumstances, benefits accounted for wrongly), an adjustment can be requested. The worker has time, as a rule until 31 March of the following year, to submit a recalculation request to the cantonal authority. It is the instrument for recovering deductions that were too high or, conversely, for regularising those that were too low.

When ordinary taxation takes over

Withholding tax at source is not always the last word. Two routes lead back to the ordinary return:

Mandatory subsequent ordinary assessment: triggered when gross income from activity exceeds an annual threshold (historically set at CHF 120,000) or where there is other significant income and wealth. From that point the withholding becomes a mere advance payment and the full return is completed.
Subsequent ordinary assessment on request: a taxpayer liable to withholding at source may request to be taxed under the ordinary procedure in order to claim deductions not covered by the tariff (payments into pillar 3a, BVG (occupational pension) buy-ins, interest on debt, training expenses). The choice must be weighed: it opens up deductions but is also binding for subsequent years.

Frequent errors

Applying an out-of-date tariff after marriage, divorce or the birth of a child.
Forgetting a second employment relationship and distorting the global rate.
Failing to submit the adjustment within the deadlines and losing the refund.
Ignoring the threshold that requires subsequent ordinary assessment.

In brief

Workers without a C permit, cross-border commuters and certain specific categories are taxed at source.
The tariff depends on marital status, children and canton, and incorporates the ordinary deductions.
An adjustment by 31 March of the following year corrects errors.
Above the thresholds or on request, ordinary taxation takes over.

How we help you

We check the tax status of your employees, apply the correct rates and handle adjustments and switches to ordinary taxation, avoiding wrong deductions and year-end surprises. Let’s put your withholding tax at source in order.