As it seems, all foreigners in Switzerland who are taxed at the source and earn LESS than 120,000 Fr. (B-permit, etc.) can now additionally file regular tax declarations, just like any Swiss citizen does. There is a fixed filing dateline of March 31 for the preceding year (no extension possible). This process is called "Nachträgliche ordentliche Veranlagung auf Antrag" (subsequent ordinary tax assessment upon request) - don't mix it up with "Quellensteuerkorrektur" (correction of withholding tax), which merely deals with errors in your monthly tax deductions at the source!
This might be a very good idea epecially for B-permit holders taxed at the source (earning less than 120,000 CHF) with irregular income on a monthly basis or for those who receive a 13th monthly salary. The "Nachträgliche ordentliche Veranlagung auf Antrag", basically an ordinary tax declaration, includes an annual wage-tax readjustment. One will still be taxed at the source on a monthly basis, however, all that will be taken into account during the tax-declaration process.
This option seems to be available to any foreigner living in Switzerland, and even for those living abroad, but earning more than 90 per cent of their income in Switzerland. However, once one has opted for filing regular tax declarations, one has to stick to this process in the future.
This is nothing new; it’s always been the case that B permit holders could file Swiss tax returns even if they earn under 120k per year. Just most people don’t bother to do so.
No, that is a new regulation. Up to 2020 only those B-permit holders who earned more than 120'000 Francs annually, owned more than 80'000 Francs, or earned more than 3'000 Francs apart from their employee activities were entitled to file a tax return. Might have depended on their respective canton.
"The reform aims to reduce unequal treatment between persons subject to withholding tax and those subject to ordinary taxation. While resident withholding taxpayers with an annual gross income of CHF 120,000 or more continue to be subject to a mandatory retrospective ordinary assessment (NOA), residents below the aforementioned threshold can now also apply for an NOA."
"Die Reform bezweckt den Abbau von Ungleichbehandlungen zwischen quellenbesteuerten und ordentlich besteuerten Personen. Während ansässige Quellensteuerpflichtige ab einem jährlichen Bruttoerwerbseinkommen von 120 000 Franken weiterhin einer obligatorischen nachträglichen ordentlichen Veranlagung (NOV) unterliegen, können neu auch Ansässige unterhalb des genannten Schwellenwerts eine NOV beantragen."
This will be very useful for many B permit holders. Previously, I had been refused to file a regular tax return, thus, in effect, paying too much tax.
Nope, was not. As explained already back in 2020, this is a new change which took effect with tax year 2021.
[2021 Changes in tax at source reassessment [Kreisschreiben 45]](http://www.englishforum.ch/finance-banking-taxation/297543-2021-changes-tax-source-reassessment-kreisschreiben-45-a.html)