U.S. tax authorities might be able to access records of their undeclared income in Switzerland following, says a formal warning by UBS to its American clients. 

The bank had agreed to hand over 4,450 account names to the U.S. government in August. Yesterday, its clients were informed that they have 20 days to select a lawyer in Switzerland, or be assigned one by the Swiss authorities. 

“The process may ultimately result in the submission of your account documents....to the IRS and the loss of the opportunity to participate in the IRS Voluntary Disclosure program,” said a source. 

Those individuals who will themselves reveal income held in tax havens, will require paying back taxes, a lesser fine and generally avoid criminal prosecution. And after the expiry of that amnesty program, any tax cheats discovered by the government face higher fines and possibly criminal prosecution.