Switzerland and Turkey have signed a double taxation agreement, containing provisions on the exchange of information set by the Organisation for Economic Co-operation and Development.

The two countries had in 2008 signed a non-OECD conformist double taxation pact, which has not yet been approved by parliament and thus never entered into force.

Following the Swiss decision in March last year to add the article on information exchange and administrative assistance of the OECD model convention, new negotiations started with Turkey to revise the existing treaty text.

This OECD provision states that the contracting jurisdictions must hand over tax information that is “foreseeably relevant for carrying out the provisions of this convention or to the administration or enforcement of the domestic laws concerning taxes of every kind and description imposed on behalf of the contracting states.”

This has previously been criticized in Switzerland for different reasons including that it substantially erodes Swiss banking secrecy and that it undermines the Swiss legal principle that foreign states can receive administrative assistance only in cases which are illegal in both countries.

The Swiss Federal Council, the country's seven-member government and collective head of state, has previously pointed out at several times that there will only be data exchange in individual cases and that so-called "fishing expeditions" will not take place.

The treaty will still have to be approved by the Swiss parliament. It may also become subject to a popular referendum in accordance with Swiss direct democracy rules.

Switzerland has by now signed more than 20 OECD-conform DTAs, although none have yet come into force.