Consider the following hypothetical scenario:
Professor A.B. is on sabbatical leave from his full time position at Canadian university. He is visiting a Swiss University from September 2011 to May 2012. During the Fall of 2011, he received 23000 chf from his host university in Switzerland. He also has income from his home university in Canada. He plans on doing the following:

1. File his Canadian tax return without declaring his 23K chf income.
2. File a Swiss tax return in which he will declare only his Swiss income of 23K chf.

Questions:
a. Will he get into trouble?
b. What is the approximate Swiss income tax on 23K chf?

As regards Swiss tax - did'nt they already deduct source tax from your remuneration? Is 23k Chf gross or net?

If he is caught, yes, as he is committing Tax Fraud.

In Switzerland, it is a tax evasion - in case he is caught he has to pay tax fine - but he would not be sent to jail..