Banking Law and International Financial Stability in Spain

1. Introduction

International financial stability means maintaining a financial system in which banks, payment systems, capital markets and other financial institutions can continue to operate safely despite economic shocks, while preventing the failure of one institution from spreading throughout other countries.

For Spain, banking stability cannot be understood only through Spanish domestic law. Spain is part of the Eurozone and European Banking Union, so Spanish banking regulation operates through several interconnected levels:

1. Spanish national banking law
2. European Union banking legislation
3. European Central Bank (ECB) supervision
4. Single Resolution Board (SRB)
5. European Commission
6. Banco de España
7. Fondo de Reestructuración Ordenada Bancaria (FROB)
8. International standards such as Basel III

Spain's principal framework includes Law 10/2014 on the regulation, supervision and solvency of credit institutions, together with directly applicable EU prudential rules. The Spanish legislation expressly connects domestic banking supervision with EU and international regulatory developments, including Basel III and the Banking Union.

2. Meaning of International Financial Stability

International financial stability involves preventing or containing:

• banking failures;
• systemic bank runs;
• excessive leverage;
• liquidity crises;
• cross-border contagion;
• sovereign-bank interaction;
• excessive concentration of financial risks;
• payment-system disruption;
• market instability;
• uncontrolled resolution of large financial institutions.

A banking crisis in Spain can have international consequences because Spanish banks may have:

• subsidiaries abroad;
• foreign shareholders;
• international creditors;
• cross-border deposits;
• exposure to international financial markets;
• connections with European payment systems.

Therefore, the law attempts to prevent an individual bank's problems from becoming a systemic crisis.

3. Spanish Legal Framework

A. Law 10/2014

The central Spanish statute is Ley 10/2014, de 26 de junio, de ordenación, supervisión y solvencia de entidades de crédito.

It regulates, among other things:

• authorisation of credit institutions;
• prudential supervision;
• solvency;
• corporate governance;
• risk management;
• supervisory powers;
• sanctions;
• intervention of troubled institutions.

The legislation identifies banks, savings banks, credit cooperatives and the Instituto de Crédito Oficial as credit institutions for its purposes.

The importance of the law for international stability is particularly clear from its legislative background: it recognises the increasing global interdependence of financial institutions and markets and the possibility that financial problems can have consequences extending beyond an individual institution.

4. Basel III and Spanish Banking Stability

The international regulatory framework is strongly influenced by the Basel Committee on Banking Supervision.

After the 2008 global financial crisis, Basel III strengthened:

• Common Equity Tier 1 capital;
• capital conservation;
• leverage controls;
• liquidity requirements;
• risk management;
• supervisory review;
• market discipline.

Spain implements much of this framework through EU legislation.

Law 10/2014 expressly explains that the EU translated Basel III into EU banking legislation through measures including Regulation (EU) No 575/2013 and Directive 2013/36/EU.

Legal significance

The basic idea is:

A bank should have sufficient financial capacity to absorb losses before those losses threaten depositors, other banks or public finances.

This is an important component of international financial stability.

5. European Banking Union and Spain

Spain's banking stability framework is closely integrated into the European Banking Union.

The three major components are:

1. Single Supervisory Mechanism — SSM

Large Spanish banks are subject to direct prudential supervision by the ECB, while Banco de España participates in the supervisory structure.

2. Single Resolution Mechanism — SRM

If a significant bank becomes failing or likely to fail, resolution may be handled through the Single Resolution Board rather than ordinary national insolvency.

3. Deposit protection

Deposit protection reduces the incentive for depositors to panic and withdraw funds simultaneously.

6. Why Bank Resolution Matters for International Stability

Traditional insolvency can cause serious disruption when applied to a large bank.

A major bank's failure can affect:

Bank A → Bank B → payment system → financial markets → businesses → households → other countries

Modern banking law therefore attempts to allow a bank to fail without allowing the financial system to collapse with it.

Resolution tools can include:

• sale of business;
• transfer of assets and liabilities;
• bridge institution;
• asset separation;
• bail-in;
• write-down of capital instruments.

This is particularly important in the Spanish context because of the experience of the financial crisis and the later resolution of Banco Popular Español.

7. Banco Popular as a Major Spanish Example

The resolution of Banco Popular Español in June 2017 is one of the most important examples for understanding Spanish banking law and international financial stability.

Banco Popular was a Spanish credit institution under direct prudential supervision of the ECB. On 7 June 2017, the Single Resolution Board adopted a resolution scheme, which was endorsed by the European Commission on the same day.

The resolution involved:

• reduction of existing capital;
• write-down/conversion of capital instruments;
• transfer of the resulting shares;
• sale of the institution to Banco Santander.

The transaction demonstrated how Spanish banking problems can be handled through the EU Banking Union's cross-border resolution architecture, rather than solely through Spanish insolvency law.

8. Bail-in and International Financial Stability

Bail-in means that shareholders and certain creditors bear losses according to the resolution framework rather than automatically relying on public funds.

This has two important purposes:

First — financial stability

The bank can be recapitalised without necessarily requiring a conventional taxpayer-funded rescue.

Second — market discipline

Investors have incentives to consider the risks associated with their investments.

However, bail-in also creates legal questions concerning:

• property rights;
• legitimate expectations;
• creditor protection;
• equal treatment;
• procedural rights;
• compensation.

The Banco Popular litigation illustrates these tensions.

9. Important Case Laws

Case 1 — Del Valle Ruíz and Others v Commission and SRB, T-510/17

Court: General Court of the European Union
Date: 1 June 2022

This case concerned challenges to the resolution of Banco Popular.

The applicants raised issues concerning:

• right to be heard;
• delegation of powers;
• right to property;
• duty to give reasons;
• legality of the resolution process.

The General Court rejected the challenge.

Importance

The case demonstrates that financial stability measures can involve substantial interference with shareholders' economic interests, but such measures remain subject to judicial review.

It illustrates the balance between:

individual property rights ↔ systemic financial stability.

Case 2 — Algebris (UK) and Anchorage Capital Group v Commission, T-570/17

Court: General Court
Date: 1 June 2022

This was another challenge arising from the Banco Popular resolution.

The applicants challenged aspects including:

• delegation;
• reasoning;
• good administration;
• right to be heard;
• property rights.

The General Court dismissed the action on the merits.

Importance

The case confirms that the resolution framework provides public authorities with significant powers to deal with failing banks, while those powers remain legally reviewable.

Case 3 — Fundación Tatiana Pérez de Guzmán el Bueno and SFL v SRB, T-481/17

This was another Banco Popular resolution case.

The applicants challenged the resolution scheme and related measures.

The General Court ultimately dismissed the actions challenging the resolution scheme.

The Court of Justice's later proceedings also addressed issues concerning admissibility and judicial review of the resolution framework.

Importance

The litigation demonstrates the importance of judicial review in maintaining a balance between:

• emergency financial intervention;
• institutional accountability;
• investor rights.

The EU courts treated the Banco Popular resolution as part of the Banking Union's legal framework rather than merely an ordinary Spanish insolvency.

Case 4 — Eleveté Invest Group and Others v Commission and SRB, T-523/17

This was another challenge arising from the Banco Popular resolution.

The applicants questioned the legality of the resolution process and its consequences for affected investors.

The General Court dismissed the action.

Importance

The case reinforces the principle that resolution authorities must operate within the statutory conditions established by EU banking-resolution law.

It also illustrates the legal difficulty of challenging emergency financial-stability decisions after they have been implemented.

Case 5 — Aeris Invest v Commission and SRB, T-628/17

This case also arose from the Banco Popular resolution.

The applicants challenged the resolution scheme and associated decision-making.

The General Court dismissed the action.

Importance

The case forms part of a group of judgments demonstrating how EU judicial review operates in systemic banking cases.

The Court's examination concerned issues surrounding the legality of the resolution process and protection of affected stakeholders.

Case 6 — Banco Santander v J.A.C. and M.C.P.R., C-410/20

Court: Court of Justice of the European Union
Judgment: 5 May 2022

This case arose from the Spanish courts and concerned the consequences of Banco Popular's resolution for claims brought by investors.

The issue involved the relationship between:

• the Bank Recovery and Resolution Directive;
• write-down of capital instruments;
• investor claims;
• the successor institution, Banco Santander.

The CJEU held that the resolution framework restricted certain post-resolution actions seeking to undo the consequences of the capital write-down in relation to share-subscription contracts.

Importance for financial stability

If investors could simply undo the legal effects of a resolution after the bank had been transferred to another institution, resolution could become legally unstable.

Therefore, the case demonstrates the principle that:

A legally effective bank-resolution mechanism must have sufficient certainty to preserve financial stability.

10. Case 7 — Banco Santander (Resolution of Banco Popular II), Joined Cases C-775/22, C-779/22 and C-794/22

Court: CJEU
Judgment: 5 September 2024

These cases concerned claims involving subordinated instruments that had been converted into shares before Banco Popular's resolution.

The Court considered:

• bail-in;
• write-down;
• conversion of capital instruments;
• shareholder and creditor protection;
• prospectus information;
• actions for damages;
• actions seeking nullity of investment contracts.

The CJEU's judgment continued the legal development concerning the effect of the resolution framework on investor claims.

Importance

The judgment demonstrates how European resolution law prioritises the legal finality of resolution measures while defining the limits of subsequent investor claims.

This is important for international financial stability because investors, banks and regulators need to know the legal consequences of a resolution decision.

11. Case 8 — Banco Santander (Resolution of Banco Popular III), C-687/23

Judgment: 11 September 2025

This was another Spanish Supreme Court reference concerning Banco Popular.

The case dealt with claims arising from financial instruments and whether certain claims were affected by the resolution measures.

The CJEU examined the interaction between:

• Directive 2014/59/EU;
• write-down of capital instruments;
• shareholder and creditor protection;
• investor claims;
• the legal successor to Banco Popular.

The judgment was delivered on 11 September 2025.

Importance

It demonstrates that the legal consequences of bank resolution can continue to generate complex litigation years after the original resolution.

This is particularly relevant to international financial stability because resolution law must balance speed and finality with legal protection for investors and creditors.

12. Conditions for Bank Resolution

Under the EU resolution framework, resolution generally requires statutory conditions such as:

1. The institution is failing or likely to fail;
2. there is no reasonable alternative private-sector or supervisory measure capable of preventing failure within the relevant period;
3. resolution is necessary in the public interest.

EU case law has expressly described these conditions in reviewing resolution decisions.

This is crucial because a government or regulator cannot simply resolve a bank whenever it considers resolution convenient.

There must be a legal basis.

13. Role of Banco de España

Banco de España plays an important role in Spain's financial-stability architecture.

Its functions include aspects of:

• banking supervision;
• prudential oversight;
• regulatory implementation;
• financial stability;
• cooperation with European supervisory authorities.

Law 10/2014 gives the supervisory framework substantial powers concerning solvency, risk management and troubled institutions.

Because Spanish banks operate within the European Banking Union, Banco de España's role must also be understood alongside the ECB and SRB.

14. Role of the ECB

The ECB is particularly important for significant Spanish banks.

The ECB's prudential supervision aims to ensure that banks maintain:

• adequate capital;
• sufficient liquidity;
• effective governance;
• sound risk management;
• compliance with prudential requirements.

The Banco Popular litigation specifically records that Banco Popular was under direct prudential supervision of the ECB.

15. Role of the Single Resolution Board

The SRB is responsible for important resolution decisions within the Banking Union.

Its purpose is to make the resolution of failing banks more predictable and coordinated.

The Banco Popular case demonstrates the importance of the SRB for Spain.

Instead of treating the failure solely as an isolated Spanish banking matter, the resolution was conducted through the EU's common resolution framework.

16. International Cooperation

International financial stability requires cooperation because banking activities are cross-border.

Spain therefore operates within a network involving:

• ECB;
• European Commission;
• SRB;
• European Banking Authority;
• Banco de España;
• FROB;
• Basel Committee;
• other national supervisory authorities.

This creates a multi-level regulatory system.

Simplified structure

International standards

↓

EU banking legislation

↓

ECB / Banking Union

↓

Spanish banking legislation

↓

Banco de España + FROB + Spanish authorities

↓

Individual banks

17. Financial Stability and Deposit Protection

Deposit protection is another important element.

A depositor who believes that a bank may collapse may attempt to withdraw funds immediately.

If many depositors do this simultaneously, a bank run can occur.

Therefore, deposit protection helps reduce panic by assuring eligible depositors that their protected deposits will be covered up to the legally applicable limit.

This has an international dimension because confidence in one country's banks can affect financial markets and banking institutions elsewhere.

18. Systemic Risk

A central concept is systemic risk.

Systemic risk occurs when problems in one institution or market spread sufficiently to threaten the financial system as a whole.

Examples include:

• interbank exposure;
• common asset holdings;
• payment-system connections;
• derivatives;
• cross-border subsidiaries;
• wholesale funding;
• liquidity dependence.

Spanish banking law therefore does not treat every bank as completely isolated.

The legislative background to Law 10/2014 expressly recognises that financial institutions and markets are increasingly globally interconnected and that difficulties can have consequences extending beyond an individual institution.

19. Relationship Between Financial Stability and Sovereign Risk

The bank-sovereign nexus is another important issue.

A weak banking system can place pressure on the government because the government may be expected to support banks.

Conversely, if the government itself faces financial stress, banks holding substantial quantities of domestic sovereign debt may also be affected.

This creates a potential feedback loop:

Weak banks → public support → sovereign pressure → weaker sovereign → weaker banks

European banking reforms attempt to reduce this type of systemic feedback.

20. Consumer and Investor Protection

International financial stability cannot be achieved simply by protecting banks.

The regulatory system must also protect:

• depositors;
• shareholders;
• bondholders;
• retail investors;
• borrowers;
• consumers.

The Banco Popular cases are particularly significant because they demonstrate the tension between financial stability and investor remedies.

The CJEU's Banco Popular judgments have dealt extensively with the consequences of bail-in and the protection of shareholders and creditors.

21. Financial Stability Versus Property Rights

One of the most important legal questions is:

Can the state or EU resolution authority interfere with investors' property in order to preserve financial stability?

The answer is not simply unlimited governmental power.

Resolution authorities must operate under statutory requirements and respect applicable fundamental rights.

The Banco Popular litigation specifically involved claims concerning the right to property, the right to be heard, and the duty to give reasons.

Thus:

Financial stability does not eliminate legal rights.

Rather, the law establishes circumstances in which certain rights may be affected, subject to legal safeguards and judicial review.

22. International Financial Stability and FinTech

Modern financial stability also involves:

• cryptocurrencies;
• stablecoins;
• digital payments;
• cloud computing;
• algorithmic trading;
• artificial intelligence;
• cyber-risk;
• third-party technology providers.

These risks can cross borders much faster than traditional banking risks.

For example, European authorities have recently raised concerns that the structure of stablecoin reserves could affect traditional bank deposits and therefore financial stability.

For Spain, this means that banking law increasingly operates alongside broader EU financial-market and digital-finance regulation.

23. Major Principles Emerging from the Case Law

24. Overall Legal Significance

Spanish banking law has evolved from a predominantly national supervisory model toward a multilevel European and international financial-stability framework.

The major lesson from the 2008 financial crisis and Banco Popular resolution is that banking stability cannot be achieved solely through traditional insolvency law.

Modern banking law therefore combines:

prudential supervision + capital requirements + liquidity requirements + risk management + deposit protection + recovery planning + resolution + bail-in + EU cooperation.

Law 10/2014 forms an important part of Spain's domestic framework, while EU legislation and the Banking Union provide the wider architecture.

The Banco Popular judgments are particularly valuable for legal study because they show how financial stability, investor protection, property rights, administrative procedure and EU banking regulation interact in practice. The General Court litigation involved several challenges to the 2017 resolution, while subsequent CJEU judgments in 2022, 2024 and 2025 dealt with the consequences of that resolution for shareholders, creditors and investors.

Conclusion

Banking Law and International Financial Stability in Spain is therefore based on the principle that the failure of a bank should not automatically become a failure of the financial system. Spanish law works together with EU and international rules to ensure adequate capital, effective supervision, early intervention and orderly resolution.

The most important case-law lesson from Banco Popular is that maintaining financial stability can justify powerful resolution measures, but those measures remain governed by statutory conditions, procedural safeguards, fundamental rights and judicial review. The resulting Spanish model is consequently not merely a system of protecting individual banks; it is a cross-border stability framework designed to protect the functioning of the wider financial system while allocating losses according to legally established rules