How the subsequent ordinary assessment works in St. Gallen
On a B permit, your employer deducts tax from your salary every month. In some cases that is not enough: you then also fill in a regular tax return, the tax office assesses your total income and assets, and the tax at source already deducted is credited without interest. This procedure is called the subsequent ordinary assessment (nachträgliche ordentliche Veranlagung, NOV).
The framework comes from federal law and applies in every canton. A tax return is mandatory once your gross salary is at least CHF 120,000 in a tax year (Art. 9 of the federal ordinance on tax at source). For married couples, each salary is tested on its own. If you move to or leave Switzerland during the year, your regular salary is converted to twelve months, while one-off payments count in full. And once you are in the NOV, you stay there until your tax at source ends. For a comparison of all cantons, see our overview of the tax return obligation when taxed at source.
This article shows what applies in St. Gallen. Status: tax year 2026, checked in October 2026.
Who has to file a tax return in St. Gallen
The St. Gallen tax act names two triggers (Art. 112bis para. 1):
- Salary. Your gross salary reaches or exceeds the federal amount. The tax manual spells it out: gross employment income of "at least CHF 120,000" (StB 105 No. 1 section D).
- Assets and income not taxed at source. Examples are interest, dividends, rental income or self-employed side income. The tax manual requires an NOV if you have such income "and/or" assets taxable in Switzerland. So one of the two can be enough.
If you are married and living together with a person who meets one of these triggers, you are assessed under the ordinary rules as well (Art. 112bis para. 3).
The St. Gallen thresholds 2026 and their sources
| Criterion | Rule in St. Gallen | Source |
|---|---|---|
| Gross salary | at least CHF 120,000 | StB 105 No. 1 section D (as of 1 January 2022); Art. 112bis para. 1 and 2 tax act |
| Assets, single | No amount published: individual check | StB 105 No. 1 section D |
| Assets, married | No amount published: individual check | StB 105 No. 1 section D |
| Income not taxed at source | No amount published: individual check | StB 105 No. 1 section D |
Checked in October 2026: tax act sGS 811.1 (version in force since 1 January 2026), tax ordinance sGS 811.11 (version since 1 January 2024), tax manual StB 105 No. 1 and StB 112 No. 1, the canton's questions and answers on tax at source (as of 3 March 2026), the canton's tax at source page (as of 4 May 2026) and application form 51.1.13a.
None of these official sources names a franc amount for assets or extra income. You will still find amounts for St. Gallen online. We did not find them in the canton's own NOV publications, so we do not use them. It is also open what exactly "assets taxable in Switzerland" means for this test and which deductions count. No NOV source of the canton says so. We clarify this case by case, with the tax office directly if needed.
What this means for you: if you have assets or income not taxed at source, there is no line below which you can be sure. Check your situation well before 31 March.
Application, form and deadline in St. Gallen
Mandatory because of assets or extra income. Here you have to act yourself. You must ask the tax authority for the tax return form by 31 March of the following year (Art. 112bis para. 4), so by 31 March 2027 for tax year 2026. The tax manual goes further: it asks you to inform the cantonal tax office "without delay" when you hold taxable assets or receive income not taxed at source (StB 105 No. 1 section IV.B.2).
Mandatory because of salary. Here your employer reports you to the tax office every year without being asked (Art. 184 lit. g). There is no such report for assets or extra income.
Voluntary application. If no trigger applies, you can apply for the NOV (Art. 112ter). Use form 51.1.13a (in German) and send it to the cantonal tax office, tax at source department, in St. Gallen. The form also has a field for extra income and assets. Once it arrives, your municipal tax office sends you the tax return; do not attach any documents to the application. Questions go to the tax at source department at ksta.quest@sg.ch.
- Deadline 31 March. The application must be filed by 31 March of the following year (Art. 112ter para. 3). The form calls this a statutory forfeiture deadline (Verwirkungsfrist). Too late means: not possible for that year.
- Moving abroad. If you leave Switzerland, the deadline ends when you deregister (Art. 112ter para. 3).
- No way back. The application cannot be withdrawn, it also covers your spouse, and in later years you are assessed under the ordinary rules automatically until your tax at source ends (StB 105 No. 1 section D; Art. 112bis para. 5).
- Moving to another canton. Under federal law, the canton responsible is the one you live in at the end of the tax year (Art. 107 para. 4 Federal Act on Direct Federal Tax).
The deadline for filing the tax return itself is a different matter. See our overview of tax return deadlines 2026 by canton.
Voluntary ordinary assessment: is it worth it?
In St. Gallen, the NOV has been the only route to additional deductions since 2021. According to the canton's questions and answers (as of 3 March 2026, in German), requests to correct tax at source for additional deductions, such as pension fund buy-ins, pillar 3a contributions or interest on debt, can no longer be filed from tax year 2021 onwards.
Applying can pay off if you have such deductions, pay for childcare or live in a municipality with a low tax rate. In the NOV, the tax office works with your actual deductions and your municipality's tax rate. Keep the commitment in mind, though: you stay in the ordinary assessment until your tax at source ends, including years in which the result is higher than the tax at source. For the pillar 3a numbers, read our article on pillar 3a for B permit holders; for the key deductions in the canton, see tax optimisation in St. Gallen.
If your issue is a wrong deduction on your payslip, for example a wrong tariff code, that is a recalculation of tax at source, not an NOV. See tax at source St. Gallen: wrong code.
An example from St. Gallen
Lena is single, lives in the canton of St. Gallen and earns CHF 95,000 gross. She holds securities worth CHF 70,000. Dividends and interest add up to CHF 1,100 in 2026.
- Salary: CHF 95,000 is below CHF 120,000. This trigger does not apply.
- Assets and investment income: St. Gallen names no amount for these. Going by the wording of the tax manual, income not taxed at source and/or taxable assets lead to an NOV. There is no line below which Lena can be sure she has nothing to do.
Result: whether Lena has to file a tax return needs an individual check. She should clarify it before 31 March 2027, because that is when she would have to request the form herself. We are happy to do that check with her.
Check your situation
The calculator on our B permit tax return page asks for your canton, marital status, salary and assets. If your salary is below CHF 120,000, it shows for St. Gallen that your case needs an individual check, because the canton names no amount.
Every case is different
Whether you have to file depends on your salary, your assets, the type of your income and your marital status. This article describes the rules for tax year 2026 and one simplified example; it does not replace individual advice. The legal basis is Art. 112bis and 112ter of the St. Gallen tax act and the tax manual StB 105 No. 1 (both in German). More information is on the canton's tax at source page.
If you would rather not fill in the tax return yourself, we can do it for you. Find out more on our page on tax advisory in St. Gallen.