As usual the tax return deadline in Switzerland is 31st of March - every year!
31st of March is the tax return deadline in Switzerland. Everyone who has reached the age of 18, is a Swiss citizen, C-residence permit holder or B-residence permit holder and earns more than CHF 120'000 p.a. or is married to one of those, is obliged to submit a tax return which is retropectively for the previous year. But do note that there other categories for tax filings but the ones mentioned are the main ones.
Married couples and those in registered partnerships will submit a joint tax return, as unlike in many other countries Switzerland does not have a spousal tax splitting. If one did not have enough time to complete the tax return or does not have all the documents together, the deadline can be extended until end of September. This is advisable as there may be a reminder fee. Under ch.ch, good information can be found and if you need help with your Swiss tax return our member Thortax Consultant is a specialist when it comes to UK/CH taxes.