Your Swiss federal, cantonal and municipal return is assessed by the cantonal tax office of your canton of residency. The cantonal tax offices determine the tax return filing due dates. Most of the cantons require filing of the tax returns by March 15 or March 31 of the following year, different due dates apply in some cantons. Most cantons allow an extension of the tax return filing due date by 2 to 6 months upon request. Extension requests can be placed with the respective cantonal tax office by phone, mail, email or online.

Your tax liability, however, is due by the end of the tax year. The exact payment due date varies by canton. Most of the cantons allow payment of the expected tax liability in installments spread across the tax year. Some cantons encourage early payment by granting discounts.