Banking Litigation in Swiss Courts — Detailed Explanation with Case Laws

1. Introduction

Switzerland is one of the world's major banking and wealth-management jurisdictions. Banking litigation in Swiss courts covers disputes between banks and customers, investors, asset managers, shareholders, employees and other financial-market participants, as well as challenges arising from regulatory and enforcement decisions.

There is no single Swiss “Banking Litigation Act.” The framework comes from several sources, principally the Swiss Code of Obligations (CO), Swiss Civil Code, Swiss Civil Procedure Code (CPC), Federal Act on Banks and Savings Banks (Banking Act), Financial Services Act (FinSA/FIDLEG), Financial Institutions Act (FinIA/FINIG), Financial Market Supervision Act (FINMASA), Anti-Money Laundering Act (AMLA), debt-enforcement legislation and private international law.

Swiss banking disputes are particularly important in areas such as:

investment losses → discretionary portfolio management → advisory liability → unauthorized transactions → bank secrecy → AML → guarantees → credit → margin calls → sanctions → insolvency → regulatory enforcement.

2. Swiss Court Structure

Banking litigation can move through several judicial levels.

Private disputes ordinarily begin before the competent cantonal court. Depending on the canton and nature of the dispute, commercial courts may have jurisdiction over qualifying business disputes.

Appeals can ultimately reach the Swiss Federal Supreme Court (Bundesgericht / Tribunal fédéral / Tribunale federale).

Regulatory disputes follow a different path. Decisions of FINMA, the Swiss Financial Market Supervisory Authority, can generally be challenged before the Federal Administrative Court, followed, where legally available, by proceedings before the Federal Supreme Court.

Thus:

Private banking dispute

Customer → Cantonal Court → Cantonal appellate level → Federal Supreme Court

while:

FINMA dispute

FINMA → Federal Administrative Court → Federal Supreme Court.

3. Contractual Foundation of Bank–Customer Litigation

Many banking disputes begin with the contractual relationship between the bank and customer.

Under the Swiss Code of Obligations, different banking activities can involve different contractual classifications.

For example, portfolio management commonly contains characteristics of a mandate relationship under Articles 394 et seq. CO.

This is important because Article 398 CO establishes duties concerning proper and faithful performance of a mandate.

A bank managing assets therefore cannot simply argue:

“Investments sometimes lose money.”

The real question may be whether the bank complied with its contractual and professional duties when making the investment.

4. Three Important Investment Relationships

Swiss case law commonly distinguishes among three situations.

Execution-only relationship

The customer independently decides what to buy or sell. The bank mainly executes instructions.

The bank's advisory responsibilities are generally narrower.

Investment advisory relationship

The bank advises, but the customer retains the final investment decision.

The bank may have duties concerning appropriate information and recommendations depending on the contractual relationship and circumstances.

Discretionary portfolio management

The customer authorizes the bank or manager to make investment decisions within an agreed mandate.

This generally creates significantly greater management obligations.

The distinction is essential because the same investment loss can produce different legal outcomes depending on the relationship.

5. Financial Services Act

The Financial Services Act (FinSA/FIDLEG) has strengthened the statutory framework governing financial services.

Among other things, it addresses client segmentation, information obligations, appropriateness and suitability requirements in relevant circumstances, documentation and accountability.

Customers are generally classified into categories such as:

• retail clients;
• professional clients; and
• institutional clients.

The level of regulatory protection differs accordingly.

FinSA does not eliminate traditional contractual litigation under the Code of Obligations. Instead, regulatory duties and private-law obligations can interact.

6. Duty to Inform

Information duties are central to Swiss banking disputes.

A customer considering a complicated investment may need information about material characteristics and risks.

However, the extent of the bank's duty depends heavily on the contractual relationship and facts.

Swiss law does not impose an unlimited obligation on every bank to protect every customer from every investment loss.

Courts typically examine questions such as:

What service did the bank promise?
What did the customer know?
What information did the bank possess?
What risk was involved?
What instructions were given?

7. Suitability and Appropriateness

Modern Swiss financial-services regulation differentiates between suitability and appropriateness assessments in circumstances covered by FinSA.

An appropriateness assessment focuses primarily on whether the customer possesses sufficient knowledge and experience concerning the relevant service or instrument.

A suitability assessment is broader and can take into account matters such as financial circumstances, investment objectives, knowledge and experience.

These requirements are particularly important in investment advice and portfolio management.

8. Portfolio Management Litigation

Portfolio-management litigation is one of the most important categories of Swiss banking disputes.

Typical allegations include:

• exceeding agreed risk limits;
• excessive concentration;
• unauthorized investments;
• failure to diversify;
• excessive trading;
• breach of investment strategy;
• conflicts of interest;
• unsuitable investments.

Suppose a conservative client authorizes a low-risk portfolio but the manager places a very large portion into speculative securities.

The resulting dispute could involve:

mandate terms → breach of duty → loss → causation → damages.

9. Proving Damages

Winning a banking claim generally requires more than proving that the bank made an error.

A claimant normally must establish the relevant elements of contractual liability, including a breach, loss and adequate causal connection, subject to the applicable rules concerning fault and burden of proof.

Investment damages can be particularly difficult.

The court may need to compare:

actual portfolio

with

hypothetical portfolio if the mandate had been properly performed.

This “but-for” analysis can require expert financial evidence.

10. Unauthorized Transactions

Another major category concerns transactions allegedly conducted without customer authorization.

Examples can include unauthorized transfers, disputed securities trades or fraudulent payment instructions.

The court may examine:

• contractual allocation of risk;
• authentication procedures;
• bank negligence;
• customer negligence;
• forged instructions;
• security procedures;
• notification obligations.

Digital banking has made these issues increasingly important.

11. Bank Secrecy

Swiss banking secrecy remains an important legal concept.

Article 47 of the Banking Act provides criminal-law protection against unauthorized disclosure of protected banking information by persons within its scope.

However, bank secrecy is not absolute.

Disclosure can be required or permitted under legal procedures involving criminal investigations, regulatory supervision, taxation and other legally recognized circumstances.

Therefore, “Swiss banking secrecy” should not be understood as a legal right to conceal unlawful assets.

12. AML Litigation

Swiss banks operate under the Anti-Money Laundering Act (AMLA) and associated regulatory requirements.

Banks must perform obligations involving:

• customer identification;
• beneficial-owner identification;
• clarification of unusual transactions;
• record keeping;
• organizational measures; and
• suspicious-activity reporting where statutory requirements are satisfied.

AML disputes may involve account restrictions, delayed transactions, customer complaints, enforcement action or regulatory consequences.

A bank can therefore face competing pressures:

customer expects transaction → bank detects risk → compliance review → transaction delayed/frozen → dispute.

The bank's contractual duties must be considered alongside mandatory financial-crime obligations.

13. FINMA Enforcement

FINMA plays a central role in Swiss financial regulation.

Where a bank or regulated person violates supervisory law, FINMA can use various enforcement tools within its statutory authority.

Regulatory proceedings differ fundamentally from ordinary damages actions.

FINMA is primarily concerned with compliance with supervisory law and protection of the financial system, whereas private courts ordinarily determine individual civil rights and liabilities.

A customer seeking compensation generally cannot assume that a FINMA finding automatically establishes the complete civil damages claim.

14. Credit and Loan Litigation

Swiss banking litigation also involves conventional lending.

Disputes can concern:

• repayment obligations;
• interest;
• security;
• mortgage enforcement;
• loan termination;
• guarantees;
• acceleration;
• valuation of collateral.

Corporate borrowers may also litigate over credit facilities and enforcement rights.

The contractual documentation is therefore crucial.

15. Margin Calls and Leveraged Investments

Leveraged investment disputes can become particularly complex.

Imagine a customer finances securities using bank credit.

Market prices collapse.

The bank demands additional collateral. The customer fails to provide it, and the bank liquidates positions.

The customer then alleges that liquidation occurred too early or at an unreasonable price.

The court may examine:

credit agreement → margin requirements → contractual liquidation powers → market conditions → bank conduct → causation.

These cases demonstrate why banking litigation frequently combines legal and quantitative evidence.

16. Swiss Case Law

Swiss Federal Supreme Court jurisprudence is particularly important because Switzerland follows a civil-law system in which legislation remains the primary formal source, while higher-court decisions provide authoritative interpretation and practical guidance.

The following decisions illustrate important banking-law principles.

Case 1 — BGE 133 III 97

This Federal Supreme Court decision is frequently discussed in connection with investment advisory relationships.

The Court examined the duties arising in the relationship between a financial institution and its customer, emphasizing that the existence and extent of advisory duties depend on the circumstances and contractual relationship.

Principle

A bank's responsibilities cannot be determined simply from the fact that it executed a securities transaction.

The court must first identify the nature of the relationship.

This gives students and practitioners the essential analytical sequence:

Classify relationship → determine duty → determine breach → examine causation and damage.

17. Case 2 — BGE 124 III 155

This decision is important in Swiss asset-management jurisprudence.

The Federal Supreme Court addressed issues associated with management of client assets and the duties owed within a mandate-type relationship.

Significance

Portfolio managers must act within the agreed mandate and exercise the required degree of care.

Investment freedom is therefore not unlimited merely because the customer has granted discretionary authority.

The agreed investment strategy remains legally important.

18. Case 3 — BGE 132 III 460

This Federal Supreme Court judgment is important in the field of asset-management and investment-loss claims.

It illustrates the difficulty of calculating damage where an investment mandate has allegedly been improperly performed.

Key lesson

The claimant cannot simply say:

“My portfolio lost CHF 1 million, therefore the bank owes CHF 1 million.”

The legally relevant loss may require comparison with the financial position the customer would probably have occupied if the mandate had been performed correctly.

This makes hypothetical portfolio analysis important in Swiss investment litigation.

19. Case 4 — BGE 138 III 755

This decision is significant for Swiss banking and asset-management law concerning retrocessions.

Retrocessions are payments received by an asset manager or financial intermediary from third parties in connection with client investments.

The Federal Supreme Court strengthened the principle that such payments may have to be passed on to the client under mandate law unless there has been a valid waiver.

Importance

The case addresses a fundamental conflict:

client interest ← asset manager → third-party remuneration

The decision contributed to major changes in Swiss wealth-management practice.

20. Case 5 — BGE 143 III 348

This decision further developed Swiss jurisprudence concerning retrocessions and related claims.

Among other matters, retrocession litigation generated important questions concerning repayment obligations and limitation periods.

Banking-law significance

Banks and asset managers need transparent remuneration structures.

A customer waiver cannot safely be treated as meaningful where the customer lacks sufficient information to understand the approximate magnitude and mechanics of the benefits being surrendered.

21. Case 6 — BGE 144 IV 294

This Federal Supreme Court judgment is important in the broader context of banking secrecy and criminal liability.

Swiss jurisprudence concerning Article 47 of the Banking Act demonstrates that banking secrecy has a strong legal foundation and that unauthorized handling or disclosure of protected client information can have serious consequences.

Litigation lesson

Banking secrecy is not merely a contractual promise between customer and bank.

It has a statutory dimension, including potential criminal consequences.

22. Case 7 — BGE 145 IV 114

This decision belongs to the important body of Swiss jurisprudence concerning financial crime and money laundering.

Such cases demonstrate the close relationship between banking operations, criminal law and AML obligations.

Practical significance

A financial institution cannot treat suspicious transactions as ordinary customer instructions where mandatory financial-crime rules require additional action.

Banking lawyers therefore need knowledge of both private banking law and criminal/regulatory law.

23. Case 8 — BGE 139 III 49

This decision is useful in understanding the consequences of mandate relationships and financial-intermediary obligations.

Swiss mandate law has repeatedly been used by the Federal Supreme Court to determine duties concerning financial management, accountability and economic benefits received in connection with the mandate.

Broader lesson

The Code of Obligations remains fundamental even after the introduction of modern financial-market statutes such as FinSA.

Regulatory legislation supplements rather than completely replaces private-law doctrine.

24. Retrocession Litigation as a Major Swiss Development

The retrocession cases deserve particular attention.

Historically, asset managers could receive payments from product providers.

This creates a possible incentive:

Is the manager selecting the investment because it is best for the client, or because it generates greater remuneration?

Swiss Federal Supreme Court jurisprudence increasingly required transparency and, under mandate principles, potentially the transfer of such benefits to the client.

Valid waivers require meaningful disclosure.

This jurisprudence has significantly influenced Swiss private banking and wealth management.

25. Burden of Proof

The burden of proof is often decisive in banking litigation.

Under the general Swiss principle reflected in Article 8 of the Civil Code, a party claiming rights from alleged facts ordinarily bears the burden of proving those facts unless another rule applies.

A customer may therefore need evidence concerning:

• contractual instructions;
• transactions;
• investment objectives;
• communications;
• losses;
• causation.

Banks similarly rely heavily on documentation.

Emails, call records, investment profiles, risk questionnaires and transaction records can determine the outcome.

26. Documentation Under FinSA

FinSA makes documentation particularly important in regulated financial services.

Financial service providers may need to document matters concerning services provided and relevant client information.

In later litigation, documentation can become critical evidence.

The practical principle is:

poor documentation = increased litigation risk.

27. Limitation Periods

Banking claims must also satisfy applicable limitation rules.

Swiss limitation law was significantly revised from 1 January 2020, including changes affecting certain contractual claims.

The precise limitation period depends on the legal basis of the claim.

Special questions can also arise in restitution, tort, retrocession and unjust-enrichment litigation.

Lawyers should therefore identify limitation issues at the beginning of a banking dispute rather than after preparing the merits.

28. Arbitration

Not all Swiss banking disputes are resolved by ordinary courts.

Commercial financing, derivatives, asset management and international banking contracts may contain arbitration clauses.

Switzerland is itself a major arbitration centre.

An international dispute can therefore follow:

banking contract → arbitration clause → arbitral tribunal → award → limited Swiss court review.

For sophisticated cross-border banking relationships, jurisdiction and dispute-resolution clauses can be as important as the substantive banking rules.

29. International Banking Disputes

Swiss banks often serve customers residing outside Switzerland.

This raises private international law questions concerning:

• jurisdiction;
• applicable law;
• consumer jurisdiction;
• choice-of-law clauses;
• recognition of judgments;
• enforcement;
• arbitration.

The Swiss Private International Law Act (PILA) is therefore highly relevant.

Depending on the case, international conventions such as the Lugano Convention can also matter.

30. Banking Insolvency

Bank insolvency differs from ordinary corporate insolvency.

FINMA has substantial responsibilities concerning bank restructuring and insolvency under Switzerland's special financial regulatory framework.

Important questions include:

depositor protection → creditor hierarchy → restructuring → resolution measures → asset realization.

The collapse of major financial institutions can therefore generate both public-law and private-law proceedings.

31. Credit Suisse and Modern Swiss Banking Litigation

The 2023 emergency acquisition of Credit Suisse by UBS created a major new chapter in Swiss financial litigation.

Particularly controversial was the treatment of approximately CHF 16 billion of Additional Tier 1 (AT1) instruments, which were written down as part of the rescue arrangements.

Investors challenged aspects of the regulatory action.

The disputes highlight major questions concerning:

• FINMA's statutory powers;
• AT1 contractual terms;
• creditor rights;
• proportionality;
• financial-stability intervention;
• constitutional/public-law protections; and
• judicial review of emergency regulatory decisions.

Because litigation surrounding the Credit Suisse measures has continued to evolve, individual procedural outcomes should be checked against the latest Swiss court decisions before relying on them professionally.

32. Private Litigation vs Regulatory Litigation

The distinction is essential:

A single banking crisis can generate both forms simultaneously.

33. Practical Litigation Method

A Swiss banking dispute can usually be analysed through the following sequence:

Step 1 — Identify the parties

Customer, bank, asset manager, director, shareholder or regulator.

Step 2 — Classify the relationship

Execution-only, advisory, discretionary management, loan, payment service or another arrangement.

Step 3 — Identify governing rules

CO, FinSA, Banking Act, AMLA, contractual terms or supervisory legislation.

Step 4 — Establish the duty

What exactly was the bank required to do?

Step 5 — Establish breach

What did it do differently?

Step 6 — Establish loss

What legally compensable damage occurred?

Step 7 — Establish causation

Would the loss have occurred without the breach?

Step 8 — Examine defences

Customer knowledge, consent, contractual allocation of risk, contributory conduct, limitation or failure of proof.

This prevents the common mistake of assuming that every investment loss equals bank liability.

34. Lessons from Swiss Case Law

The major jurisprudential themes can be summarized as follows:

BGE 124 III 155
→ portfolio-management duties must be assessed against the mandate.

BGE 133 III 97
→ the bank's duties depend heavily on the type and circumstances of the client relationship.

BGE 132 III 460
→ investment damages require careful counterfactual analysis.

BGE 138 III 755
→ retrocessions can belong to clients under mandate principles unless effectively waived.

BGE 143 III 348
→ retrocession and limitation issues have major practical consequences.

BGE 144 IV 294
→ banking secrecy has statutory and criminal-law significance.

BGE 145 IV 114
→ banking activity must be considered alongside AML and financial-crime law.

Together, the cases show that Swiss banking litigation cannot be reduced to one body of law.

35. Conclusion

Banking litigation in Swiss courts is a sophisticated combination of contract law, financial regulation, civil procedure, administrative law, AML law, bank secrecy, insolvency law and private international law.

The Swiss Code of Obligations remains central to customer-bank and asset-management disputes, while the Banking Act, FinSA, FinIA, FINMASA and AMLA provide the modern regulatory framework.

Swiss Federal Supreme Court jurisprudence—particularly BGE 124 III 155, BGE 132 III 460, BGE 133 III 97, BGE 138 III 755 and BGE 143 III 348—has been especially influential in defining portfolio-management responsibilities, advisory duties, calculation of investment losses and the treatment of retrocessions.

The central principle is:

A financial loss alone does not establish bank liability.

A claimant normally needs to establish the relevant legal duty, breach, legally recognizable loss and causal connection. Equally, banks cannot rely simply on the inherent risks of investment when they have violated contractual, statutory or regulatory obligations.

Modern disputes surrounding Credit Suisse, AT1 instruments, digital banking, cross-border wealth management and regulatory enforcement show that Swiss banking litigation continues to evolve from traditional bank-customer disputes toward complex questions of financial stability and public regulatory power.