Switzerland has signed the first of 12 double taxation agreements needed in order for it to conform to international cooperation standards.
The agreement with Denmark was signed by both parties on Friday.
Switzerland agreed in March to meet tax transparency standards set by the Organisation for Economic Co-operation and Development after being placed on its grey list of uncooperative tax havens.
The cabinet has approved similar agreements with five more countries, based on the OECD model tax convention.
The Danish accord is the first to include a clause about increased cooperation in sharing customer data with another government. Switzerland also announced talks would begin on September 8 on a new agreement with Germany, a strong opponent of Swiss banking secrecy laws.
Switzerland has additionally initialled double taxation accords with Qatar, Finland, Luxembourg, Norway, France, Mexico, the United States, Japan, The Netherlands, Poland, Britain and Austria, but they still have to be signed.
However, parliament will have the final say.
swissinfo.ch and agencies
In compliance with the JTI standards