Banking Law and Constitutional Limits on Banking Supervision in Spain

Introduction

Banking supervision in Spain operates within a distinctive two-level constitutional and European legal structure. At national level, the Banco de España exercises supervisory responsibilities under the Spanish Constitution, Law 13/1994 on the Autonomy of the Banco de España, and Law 10/2014 on the regulation, supervision and solvency of credit institutions. At European level, since 4 November 2014, Spain has participated in the Single Supervisory Mechanism (SSM), under which the European Central Bank (ECB) and national competent authorities jointly supervise banks.

The ECB directly supervises Spain's significant credit institutions, while the Banco de España normally exercises direct microprudential supervision over less significant institutions subject to ECB oversight. The ECB nevertheless retains important powers throughout the system and is responsible for matters such as certain authorisations and withdrawals of banking licences.

Banking supervisors therefore possess extensive powers, including obtaining information, carrying out inspections, assessing governance and risks, requiring additional capital, imposing corrective measures and applying sanctions. These powers are not unlimited. They remain constrained by the Spanish Constitution, EU law, fundamental rights, proportionality, procedural fairness, judicial review and constitutional rules allocating powers between the State and Spain's Autonomous Communities.

Constitutional Basis of Banking Supervision

The principal constitutional foundation is Article 149.1.11 of the Spanish Constitution, which reserves to the State competence over the basic rules governing credit, banking and insurance. Article 149.1.13 additionally gives the State competence over the bases and coordination of general economic planning.

These provisions allow national authorities to establish uniform prudential requirements necessary to protect the stability of the Spanish financial system. The Constitutional Court has nevertheless repeatedly stressed that the concept of “basic legislation” cannot automatically be expanded until regional powers disappear.

The statutory framework reflects this structure. Article 7(6) of Law 13/1994 assigns the Banco de España responsibility for supervising solvency and compliance with banking legislation. Articles 50–60 of Law 10/2014 regulate its supervisory responsibilities, while Article 68 and following provisions establish important prudential intervention powers.

Consequently, banking supervision is constitutionally legitimate because financial stability constitutes a major public interest, but regulatory necessity does not give supervisors unlimited authority.

Principle of Legality

One of the most important constitutional limits is the principle of legality. Supervisory agencies can exercise only powers granted by law or directly applicable EU legislation.

A supervisor cannot create unrestricted enforcement authority simply because doing so might promote financial stability. Decisions concerning capital requirements, governance, authorisations, sanctions or intervention must have an identifiable legal foundation.

This principle is particularly important where sanctions are concerned. Because administrative penalties constitute an exercise of punitive public authority, constitutional guarantees associated with Article 25 of the Constitution require sufficiently clear legal rules defining infringements and sanctions.

Administrative discretion therefore exists, particularly where complicated assessments of solvency, liquidity or systemic risk are necessary, but discretion must remain within statutory boundaries.

Proportionality and Protection Against Arbitrary Supervision

Banking supervision frequently involves predictive assessments. A bank need not already be insolvent before supervisors intervene. For example, Law 10/2014 permits prudential intervention where sufficient grounds indicate that an institution may breach specified obligations.

Nevertheless, supervisors must select measures proportionate to the risks involved.

This means that requiring additional capital, restricting distributions, replacing managers or imposing sanctions should be connected rationally to the supervisory problem identified.

The constitutional prohibition of arbitrariness contained in Article 9.3 means that technically difficult banking decisions cannot become legally unreviewable merely because they involve supervisory expertise.

Right to a Fair Procedure and Defence

Article 24 of the Spanish Constitution protects effective judicial protection and fundamental procedural guarantees. Comparable protections apply through EU law and the Charter of Fundamental Rights.

The SSM Regulation expressly incorporates procedural safeguards. Under Article 22 of Regulation 1024/2013, before adopting a supervisory decision the ECB ordinarily must provide affected persons with an opportunity to be heard. Decisions should generally rely only upon objections on which those persons have had an opportunity to comment.

Affected parties are also entitled to exercise defence rights and obtain access to the supervisory file, subject to legitimate confidentiality restrictions. Urgent provisional intervention is possible where necessary to prevent significant damage to the financial system, but procedural guarantees must subsequently be provided as quickly as possible.

Thus, urgency can modify the timing of due process but ordinarily cannot eliminate it.

Judicial Review as a Constitutional Limit

Supervisory independence does not mean immunity from judicial control.

Spanish administrative measures adopted by the Banco de España can ultimately be reviewed by the competent courts under the administrative judicial system. Article 106 of the Constitution embodies the broader constitutional principle that courts control the legality of administrative action.

ECB supervisory decisions are instead subject to the EU judicial system, particularly actions for annulment under Article 263 TFEU.

Courts normally recognise that supervisors possess technical expertise, particularly regarding risk assessments. Nevertheless, they can examine whether the supervisor had jurisdiction, respected procedural requirements, correctly interpreted applicable law, properly established relevant facts and respected proportionality.

This distinction between technical discretion and unlimited discretion is fundamental.

Division of Powers Between the State and Autonomous Communities

One particularly important Spanish constitutional limitation concerns the distribution of supervisory powers.

Historically, savings banks or cajas de ahorros generated significant constitutional litigation because Autonomous Communities possessed important powers concerning their organisation and activities while the State was responsible for the basic regulation of banking and credit.

The Constitutional Court developed the principle that financial stability can justify significant national powers, including certain executive responsibilities of the Banco de España, but national authorities cannot use financial stability as a general justification for eliminating constitutionally protected regional competence.

Major Case Law

1. STC 1/1982

This early Constitutional Court judgment concerned regulatory powers relating to savings banks. The Court recognised that matters involving interests extending beyond a single Autonomous Community could fall within State responsibility and accepted an important role for the Banco de España in ensuring nationally coordinated banking regulation.

The decision established an early constitutional foundation for central supervisory authority while recognising the territorial structure established by the Constitution.

2. STC 48/1988

This is one of the leading Spanish cases concerning banking powers.

The Constitutional Court held that Article 149.1.11 enables the State to establish the basic regulation of credit and banking. Importantly, it accepted that, exceptionally, some regulatory provisions and even certain executive functions performed by the Banco de España could constitute part of those “basic” rules where necessary for the effective functioning of credit institutions or national financial policy.

But the Court simultaneously rejected the proposition that the State could use the concept of basic banking regulation to achieve complete regulatory uniformity.

The decision therefore illustrates both the constitutional strength and the constitutional limitation of central banking supervision.

3. STC 49/1988

This companion judgment examined competence concerning the discipline, inspection and sanctioning of savings banks.

The Court emphasised that the allocation of constitutional powers derives from the Constitution and Statutes of Autonomy rather than simply from ordinary legislation. Parliament therefore cannot redraw the constitutional distribution of powers merely by declaring particular functions to belong exclusively to national authorities.

The judgment remains significant because it subjects supervisory institutional design itself to constitutional review.

4. STC 178/1992

Here the Constitutional Court dealt with supervisory powers involving savings-bank reserves and related authorisations.

It acknowledged that some decisions contained a particularly high degree of technical discretion and required evaluation from a unitary national perspective. Such executive responsibilities could therefore legitimately remain with the State and Banco de España where necessary for the coherent functioning of the national credit system.

The case shows why some central supervisory powers can themselves acquire a constitutionally “basic” character.

5. STC 182/2013

This judgment provides an especially clear statement of the constitutional limitation on central supervisory authority.

The Court considered measures associated with banking restructuring and rejected an arrangement that effectively excluded relevant Autonomous Community participation. It declared that neither the State nor an Autonomous Community possesses an omnipotent or purely discretionary authority over matters involving overlapping competences.

Instead, cooperation mechanisms must enable each authority to exercise its constitutionally allocated functions. Financial emergencies therefore do not automatically extinguish Spain's territorial division of powers.

6. Landeskreditbank Baden-Württemberg v ECB, Case C-450/17 P (2019)

Although arising outside Spain, this CJEU judgment directly governs the SSM structure applicable to Spanish banks.

Landeskreditbank challenged its classification within the ECB supervisory structure. The litigation clarified the extensive role conferred upon the ECB by Regulation 1024/2013 and the relationship between the ECB and national competent authorities within the SSM.

The Court dismissed the appeal, reinforcing the integrated nature of European banking supervision. At the same time, the litigation demonstrates that ECB decisions regarding the allocation and exercise of supervisory responsibilities remain subject to EU judicial review.

7. Berlusconi and Fininvest v Banca d'Italia, Case C-219/17 (2018)

This case is particularly important for understanding judicial protection in composite supervisory procedures, where a national authority conducts preparatory work but the final decision belongs to the ECB.

The Court held that where national preparatory measures form part of a procedure culminating in an ECB decision, the EU Courts have jurisdiction to review whether defects in those national preparatory measures affect the legality of the final ECB decision.

For Spain, the principle means that cooperation between Banco de España and the ECB cannot create a gap in judicial accountability.

8. ECB v Trasta Komercbanka, Joined Cases including C-663/17 P (2019)

The litigation followed the withdrawal of a bank's authorisation and concerned, among other matters, access to judicial review and representation of the institution challenging the ECB measure.

The Grand Chamber's judgment illustrates the constitutional importance of effective judicial protection even when exceptionally strong supervisory action, such as licence withdrawal, has been taken.

Independence Versus Accountability

Banco de España and the ECB require significant institutional independence because politically motivated supervisory decisions could undermine financial stability.

But independence is not the same as unlimited power.

The SSM framework combines independence with procedural safeguards, parliamentary accountability mechanisms, reasoned decisions and judicial control. Regulation 1024/2013 expressly preserves accountability arrangements for national competent authorities concerning functions remaining under national responsibility.

Supervisors therefore operate under an institutional principle that may be described as independence in decision-making combined with accountability under law.

Economic Freedom and Property Rights

Intensive supervision can interfere with protected economic interests. Capital restrictions can affect distributions to shareholders; governance measures can remove directors; licence withdrawal can effectively terminate a banking business; restructuring measures may substantially affect ownership interests.

Article 38 of the Constitution recognises freedom of enterprise, while Article 33 protects property.

Neither right prevents prudential banking regulation. Banking is an unusually regulated activity because bank failures can affect depositors, payment systems and the wider economy. Nevertheless, interference must have adequate statutory authority, serve a legitimate public interest and satisfy proportionality requirements.

Constitutional rights therefore constrain the manner and intensity of intervention rather than creating immunity from supervision.

Practical Constitutional Test

A Spanish banking supervisory action should generally satisfy six interconnected requirements: it must come from the legally competent authority; possess a sufficient statutory or EU legal basis; pursue a legitimate prudential objective; respect procedural and defence rights; be necessary and proportionate to the identified risk; and remain subject to effective judicial review.

Failure at any of these stages can transform otherwise legitimate prudential supervision into unlawful administrative action.

Conclusion

The constitutional law of banking supervision in Spain attempts to reconcile two competing necessities: strong supervision capable of protecting financial stability and constitutional restraints capable of preventing excessive public power.

Banco de España and the ECB possess substantial powers to inspect banks, assess risk, impose prudential requirements, sanction infringements and intervene when financial stability is threatened. Law 10/2014 expressly establishes a wide supervisory framework, while the SSM places Spanish banking supervision within an integrated European system.

Yet those powers remain limited by legality, proportionality, defence rights, judicial protection, economic freedoms and the constitutional distribution of competences.

Spanish Constitutional Court judgments such as STC 48/1988, STC 49/1988, STC 178/1992 and STC 182/2013 establish that even compelling objectives such as national financial stability do not create unlimited State authority. At European level, Landeskreditbank, Berlusconi/Fininvest and Trasta Komercbanka demonstrate that the extensive powers conferred on the ECB under the SSM remain embedded within a system of procedural guarantees and judicial review.

The central constitutional principle is therefore clear: effective banking supervision is constitutionally legitimate and economically necessary, but supervisory effectiveness must be achieved through law rather than outside it.