How the subsequent ordinary assessment works in Zug
On a B permit, your employer deducts tax from your salary every month. Once your situation is no longer simple, you also file a normal Swiss tax return. This is called the subsequent ordinary assessment (nachträgliche ordentliche Veranlagung, NOV). The Zug tax administration then assesses you with your actual income, assets and deductions, and credits the tax at source already deducted without interest.
The federal framework is the same in every canton. If your gross salary reaches CHF 120,000 or more in a tax year, you are assessed under the ordinary rules (federal Ordinance on Tax at Source, Art. 9). For married couples, each salary counts on its own. If you were only taxable in Switzerland for part of the year, your regular salary is scaled up to twelve months for this test, while one off payments such as a bonus count as paid. And once in the NOV means: in the NOV until tax at source ends for you. The rules of all cantons side by side are in our guide to the canton thresholds.
Zug has no ordinance of its own on tax at source. The rules are in the Zug Tax Act (§§ 86 and 87) and in an overview published by the tax administration. This article shows what follows for you. Tax year 2026, checked October 2026.
Who has to file a tax return in Zug
Below a salary of CHF 120,000, the Zug Tax Act makes a tax return mandatory if you have assets and income that are not taxed at source (§ 86 para. 1 lit. b). The amounts are in the tax administration's overview of the subsequent ordinary assessment (Annex II, 2026 edition, in German), footnote 1: you are assessed if your taxable income not taxed at source is CHF 2,000 or more or your taxable assets are CHF 100,000 or more. One of the two is enough.
- Income not taxed at source of CHF 2,000 or more: interest, dividends or rent of this amount make a tax return mandatory.
- Taxable assets of CHF 100,000 or more: this one is less clear cut. The overview speaks of “taxable assets” and of “assets subject to tax under cantonal law”, but does not say which deductions apply. If your assets after debts reach CHF 100,000, your case needs an individual check.
For married couples, the overview does not name a higher amount, only a joint NOV. It does not say explicitly how a couple's assets are combined for the threshold. We clarify that for your case as well.
Important: if you are above one of these lines, you have to act. The Tax Act requires you to request the tax return forms from the cantonal tax administration by 31 March of the following year (§ 86 para. 3).
Zug thresholds 2026 and their sources
| Condition | Threshold | Source |
|---|---|---|
| Gross salary, per person | CHF 120,000 or more | Federal QStV Art. 9 para. 1; Zug Tax Act § 86 para. 1 lit. a; NOV overview |
| Taxable income not taxed at source | CHF 2,000 or more: mandatory | NOV overview (Annex II, 2026 edition), footnote 1 |
| Taxable assets | CHF 100,000 or more; reached after debts: individual check | NOV overview (Annex II, 2026 edition), footnote 1 |
| Assets, married | no separate amount named | NOV overview, column “Gemeinsame NOV bei Ehegatten” |
The overview itself carries no year. The year is in the file name (“2026_info_250_NOV_Uebersicht”), and the file dates from November 2025. The general guide to the tax return (Wegleitung) is not a source for this question and was not used here.
A note on the salary line: the tax administration's information sheet 100 for employers (December 2025) says “more than CHF 120,000”. The Tax Act says “reaches or exceeds”, and the federal ordinance says “at least”. The law and the ordinance are binding: the obligation starts at exactly CHF 120,000.
If you moved here during the year, only federal law regulates the scaling, and only for the CHF 120,000. Zug sets no rule for the CHF 2,000 or the CHF 100,000. We clarify that for your case.
Application, form and deadline in Zug
For both routes, the mandatory one and the voluntary one, Zug uses the same form 250 “Antrag auf nachträgliche ordentliche Veranlagung” (in German). Under “Begründung” you tick whether you have further income or assets not taxed at source (Art. 89 DBG) or want to be assessed voluntarily (Art. 89a DBG).
- Deadline: 31 March of the following year, so 31 March 2027 for the tax year 2026 (Zug Tax Act § 86 para. 3 and § 87 para. 3). According to information sheet 100, no extension is possible for applications.
- Signature: married couples and registered partners both sign (form 250, important notes). The application also covers your spouse (§ 87 para. 2).
- Leaving Switzerland: the deadline for the application ends when you deregister (§ 87 para. 3).
- Moving within Switzerland: the cut off date principle applies. The canton where you live at the end of the tax period or of your tax liability is responsible for the whole year (information sheet 100, page 2).
The responsible office is the Steuerverwaltung des Kantons Zug, Gruppe Quellensteuer, Bahnhofstrasse 26, 6300 Zug, internet.stv@zg.ch, phone +41 41 594 30 00 (page Quellensteuerpflichtige Person).
One pitfall: because the same form serves both cases, the mandatory case is easy to overlook. If your salary is below CHF 120,000 and your extra income is above the line, it is mandatory, and the 31 March deadline applies just the same.
Choosing the ordinary assessment voluntarily: is it worth it?
In Zug, the NOV on application has no conditions (NOV overview; Zug Tax Act § 87 para. 1). Information sheet 100 names deductions such as pillar 3a contributions, maintenance payments and further training costs as examples. Without an application you do not get them: tax at source then replaces the ordinary tax on your employment income, and no additional deductions are granted later (§ 87 para. 4). How the numbers work for pillar 3a is in our article on pillar 3a with a B permit.
Think this step through. You can apply only once, and the application cannot be withdrawn (form 250; information sheet 100). After that you file a tax return every year until tax at source ends for you, and according to the overview, as a couple even after a separation or divorce.
Example from Zug
Marco is single, lives in Baar and earns a gross salary of CHF 105,000 in 2026, so below CHF 120,000. His securities account pays him interest and dividends of CHF 2,400 in total in 2026.
The CHF 2,400 is income not taxed at source and above the Zug line of CHF 2,000. Marco therefore has to request the tax return with form 250 by 31 March 2027 and is assessed under the ordinary rules for 2026. Whether his portfolio also reaches the asset line would need checking, but it does not change the result here: one line is enough.
Check your own case
The calculator on our page about the tax return with a B permit opens with Zug selected. It asks for your civil status, salary, assets and income and shows you whether you need to act or whether we should look at your case together.
Sources and status
All information applies to the tax year 2026 and was checked in October 2026. This article does not replace individual advice. The official documents are in German.
- Annex II, overview of the subsequent ordinary assessment (NOV), Zug tax administration, 2026 edition (file dated 26 November 2025), footnote 1
- Information sheet 100 for employers on tax at source as of 1 January 2026, December 2025
- Form 250, application for the subsequent ordinary assessment, 2026 edition
- Zug Tax Act (BGS 632.1), in force since 1 January 2026, § 86 and § 87
- Zug tax administration page for people taxed at source
- Federal Ordinance on Tax at Source (SR 642.118.2), Art. 9 and 10
Rather not fill in the tax return yourself? We take care of it for you, see your Zug tax return with FIN.