The Swiss tax office has agreed to a request from the Netherlands to hand over information about Dutch nationals with accounts at the biggest banking group in Switzerland, UBS.

The request targets Dutch nationals who have had more than €1,500 on their accounts over the past two years and did not reply to a letter from the Swiss authorities about potential illicit savings, the Financieele Dagblad says.

The UBS application is the first to be made under the revised Swiss LAAF legislation on exchanging tax information, the paper says. The Dutch tax office is planning to approach more Swiss banks about accounts held by Dutch nationals.

The Netherlands was operating an amnesty for people with secret bank accounts abroad but the rules for ‘legalising’ illicit savings have been toughened up since July 1.

Since 2011, €5.5bn held in secret bank accounts abroad has been ‘legalised’ by the tax office, generating over €600m for the treasury, according to the tax office’s latest report in September.

When the government first announced it would tackle secret bank accounts, there was no fine for people who confessed. Now, however, people have to pay a 60% fine as well as tax on their secret savings.