The practitioner’s perspective

Defence against mutual assistance and administrative assistance

For persons whose accounts in Zurich are the subject of a foreign request, the first step is to understand which channel is being used. A request under the Mutual Assistance Act, a request under a double taxation agreement and a request from FINMA’s foreign counterpart follow different rules. They have different standards of relevance, different rights of participation and different appeal routes. Defence counsel must also assess whether the foreign proceedings create risks for the client beyond the immediate request, for example because the information may later be passed on to tax authorities or used in civil claims.

In criminal mutual assistance, the most promising arguments concern the conditions of dual criminality and speciality and the scope of the documents to be transmitted. A foreign request that describes pure tax evasion without any element of fraud can be resisted. Documents that relate to accounts or periods without any connection to the facts described can be excluded. Where the requesting state’s proceedings raise concerns under the European Convention on Human Rights, the defence can seek guarantees under Article 80p of the Act. In the appeal to the Federal Criminal Court, the arguments must be complete, because the Federal Supreme Court will intervene only in exceptional cases. Counsel should also take into account that tactical appeals are well known to the authorities. The Federal Audit Office has documented the use of appeals as a delaying tactic, which affects the credibility of arguments that appear to serve that purpose.

In administrative assistance in tax matters, the scope for defence is narrower. The Federal Supreme Court applies the principle of good faith in favour of the requesting state and construes foreseeable relevance broadly. Defence counsel should examine whether the request meets the formal requirements of the treaty, whether it concerns tax periods covered by the treaty and whether the data on which it is based were obtained in circumstances that engage Article 7 letter c of the Act. The client should also be advised early on to regularise his situation in the state of residence. Once information has been exchanged, a voluntary disclosure may no longer be possible or may lose its effect.

Cross-border asset tracing

For claimants, successful asset tracing in and from Zurich usually combines several instruments in a planned sequence. The first phase consists of gathering information abroad, through Section 1782 applications in the United States, disclosure orders in England or offshore jurisdictions, or the files of foreign criminal proceedings. In the second phase, the claimant uses this information to act in Switzerland. The options are a criminal complaint in Zurich, which allows the prosecutor to freeze accounts and obtain bank documents, an attachment of identified assets, or, in the case of an insolvent company, the recognition of the foreign insolvency proceedings. The third phase concerns enforcement, through recognition of the foreign judgment under the Lugano Convention or the Private International Law Act, or through the return of forfeited assets to the victim in the criminal proceedings.

The main risk is the leakage of information before the assets are secured. Swiss banks are subject to anti-money laundering duties which, as the previous chapters show, often lead to the freezing of accounts once suspicious facts come to light. A claimant who informs the bank about a fraud before obtaining an attachment or a criminal freeze may therefore trigger a report to the Money Laundering Reporting Office and a freeze, but may also alert the account holder if the bank terminates the relationship. The timing of the different steps is therefore decisive.

For international clients, counsel with experience of common law and civil law systems has a real advantage. Practitioners who have worked in London, Singapore or Hong Kong know the scope of Norwich Pharmacal orders and worldwide freezing injunctions and can combine them with Swiss instruments. This dual perspective is particularly useful in cases involving Asian clients who hold assets through structures in Singapore, Hong Kong or the British Virgin Islands with bank accounts in Zurich.

The advisory side

Cross-border cooperation also shapes advisory work. Financial institutions in Zurich must decide how to respond to foreign subpoenas and whether a request from a foreign authority can be answered directly under Article 42c of the Financial Market Supervision Act or requires authorisation under Article 271 of the Criminal Code. Trustees and family offices must consider how their structures appear in the automatic exchange of information and in requests for administrative assistance. Asset managers must understand that a client’s assets may be frozen under the Foreign Illicit Assets Act if the client or a close associate becomes a politically exposed person in a state whose government falls. These questions require the same combination of criminal, tax, regulatory and private international law that runs through this chapter.

For general information only. This article does not constitute legal or tax advice, does not replace advice on an individual case and creates no lawyer-client relationship. It reflects the legal position as of September 2025.