In the context of their international business activities, Swiss credit institutions may be required to prove to foreign states (in particular the USA) that they comply with their sanctions provisions. Otherwise, their business access to the state may be impeded under certain circumstances. In this context, a Swiss credit institution considered voluntarily transmitting transfer data to the U.S. in the context of international payment transactions in which it acted as a transfer bank. After clarifying the facts and the legal situation, we came to the conclusion that only a voluntary transmission of anonymized transfer data is permissible to prove compliance with sanction conditions.