If you are carrying cash of more than € 10000 or the equivalent in other currencies, travellers´ cheques or bearer negotiable instruments, when departing or arriving in Iceland, you are obliged to declare it to the customs in Iceland at the point of departure or arrival.
You can fill out the declaration here on the web, print and give it to a customs officer at the point of departure or arrival.
The declaration form is also available at the RED customs gate.
The purpose of obtaining information in this respect is to help combat money laundering and is preventive measures of the Icelandic government against drug traffic and terrorist threats and other unlawful acts crossing border.
Customs officers are authorized to seize these valuables when there is suspicion that they will be used for violations of provisions punishable by the General Penal Code, cf. Customs Law No. 88/2005, Article 162. Such cases are submitted to the police for processing.
These measures apply in all of the major trading countries of Iceland.