Two strong effects that do not cancel out
In some cantons a wrong tariff letter and missing child allowances almost offset each other. Not in St. Gallen. Both effects are substantial here, but of different size — which is why one of the largest overpayments in our series remains at the end.
The use case
A married couple, both working, three shared children they can claim, salaries of CHF 174'000 and CHF 157'000. The husband's payslip shows B2 — married single earner with two children. The wife's shows C0: right letter, but no children. Both should have been C3.
Calculated with the official St. Gallen 2026 tariffs without church tax, assuming twelve equal monthly salaries with no 13th salary and no bonus:
- Husband: 9.41 % instead of 11.62 % — around CHF 3'845 too little a year
- Wife: 14.89 % instead of 10.46 % — around CHF 6'955 too much a year
- Together: around CHF 3'110 too much
Where the difference comes from
On the husband's payslip two entries are wrong at once, and they work against each other: the wrong letter deducts too little — B3 against C3 is 3.81 percentage points at his salary. The missing third child deducts 1.60 points too much in the other direction. That leaves 2.21 points too little.
On the wife's payslip the letter is right and only the three children are missing. That comes through in full, at 4.43 percentage points, with nothing working against it. Which is why her overpayment dominates so clearly.
For comparison: in Aargau the two amounts sit almost level and only CHF 118 remains. In St. Gallen it is CHF 3'110.
How the St. Gallen tariff is built
St. Gallen has no tax-free zone at the bottom. The tariff applies from the first franc of salary, where Geneva, Zug and Schwyz each leave roughly the first CHF 2'500 out. On top of that the canton sets a minimum of CHF 5.00 a month: if the percentage calculation produces less, the five francs are deducted anyway.
Neither detail moves the numbers much for a household on CHF 174'000 and CHF 157'000. Both matter for part-time and hourly work, where the monthly base is small — a second job or an irregular month is taxed here from the first franc.
Above CHF 124'501 a month the scale reaches its ceiling of 25.88 % and stops rising. Below that, which covers essentially every salary in this use case, both the letter and the number of children still move the rate.
What these figures are — and what they are not
They concern the running tax-at-source deduction, not the final tax. Because one spouse in this use case already earns more than CHF 120'000, the couple is assessed under the ordinary rules anyway — and the tax at source actually paid is credited there. The wrong code affects the household's liquidity first.
How to check your payslip
The tariff code has three parts: tariff letter, number of children you can claim, church tax marker. Check all three against your actual situation — and on both payslips, not just the conspicuous one.
A correct code is a good first check but not a complete one: with several employments the rate-determining income can be wrong too. In St. Gallen the tariff bites from the first franc, so part-time and secondary employment deserve the same look as the main salary. If you find something, report it to HR. For years already closed, a tax-at-source correction should generally be requested by 31 March of the following year. And what you will actually owe in the end only shows once both salaries are calculated together — see our tax advisory for St. Gallen.