A tax return must be filled in for every year of business. The forms are sent out around February of the following year and must be returned by 30 September of the following year. It is possible to extend this deadline until the following 31 March and can be made oneself via the internet. For further information see: Fristerstreckung - German

The tax return may be filled in electronically. The Cantonal Tax Office makes eTax.Zug software available to the taxpayers for this purpose every year free of charge, see eTax.Zug - German

The due dates of the taxes depend on the year–end closing date:

• Year-end closing date in 1st term
  1st September of the current year (payment period - 30 days)
• Year-end closing date in 2nd term
  1st March of the following year (payment period - 30 days)

The taxpayers receive provisional bills with the estimated amount of tax to be paid. Once the final assessment is clear, final tax bills are sent out. Where too much tax has been paid, this will be returned or carried over to another tax period. Where too little tax has been paid, a bill will be issued later.