Swiss banking secrecy is based on the bank's duty of confidentiality towards the customer, the customer's privacy rights, and the Federal Banking Code, which makes any breach of banking secrecy a criminal offence. These legal bases are as undisputed as the fact that banking secrecy is by no means absolute.
In a recent case, the Swiss Federal Supreme Court had the opportunity to further clarify the basis and the limits of Swiss banking secrecy. In connection with the 'mani pulite' bribery scandal in Italy, the Italian authorities asked the Swiss authorities for assistance. The Swiss authorities ordered several banks to disclose information about the accounts of various Italian customers. One of the customers involved opposed the order and appealed to the Federal Supreme Court, advancing two principal arguments. First, that banking secrecy is a right protected by the Swiss Constitution; second, that banking secrecy is a matter of Swiss national policy and prevails over Italy's interest in prosecuting wrongdoers.
The Federal Supreme Court rejected both arguments, specifying the basis and scope of banking secrecy as follows:
- Banking secrecy is not a constitutional right, only a right protected by statutory provisions. Therefore it does not generally prevail over competing interests and may have to take second place to the legal obligations of Switzerland as set out in international treaties.
- When assessing the interests involved the Court made it clear that mere disclosure of some bank customers' data does not endanger the vital state interests of Switzerland and thus does not violate Swiss national policy. Indeed, the Court held that the reputation of Switzerland would be damaged if criminal money could be safely hidden in Switzerland.
Summing up, the Supreme Court said: "If all the conditions for judicial assistance in criminal matters — in particular the requirement that human rights are respected in the criminal proceedings of the state requesting judicial assistance — are met, there can only rarely be reason to refuse judicial assistance on the basis of Swiss banking secrecy alone."