Switzerland’s highest court has ruled that banking group USB must forward information about Dutch savers to the Dutch tax office, overturning a lower court decision.

Last November, the Netherlands requested information about Dutch nationals who had more than €1,500 in their accounts and had not answered a letter from the Swiss authorities about potentially illicit savings.

Switzerland agreed to comply on the basis of a tax treaty between the two countries, but one USB client went to court to have the information transfer stopped.

The lower Swiss court ruled the agreement is too general in scope because it does not name specific account holders. The five year old tax deal between the Netherlands and Switzerland, the court said, is not enough grounds for such a broad request.

However, the supreme court said on Monday the Dutch request only required information to identify account holders, not specific names.

The Dutch finance ministry said in a reaction it is pleased with such a ground-breaking decision. It also means that a second request for information sent to Credit Suisse will be honoured, the ministry is quoted as saying.