Banking Law and Green Finance Regulation in Spain

1. Introduction

Green finance refers to banking, lending, investment and capital-market activities that support environmental objectives such as climate-change mitigation, renewable energy, energy efficiency, sustainable transport, pollution prevention and the transition toward a lower-carbon economy.

In Spain, green finance regulation is not contained in one single “Green Finance Act.” Instead, it operates through a combination of Spanish banking and climate legislation and directly applicable European Union rules. Banco de España currently identifies Spain’s Sustainable Economy Law 2/2011, Climate Change and Energy Transition Law 7/2021, and the 2025 order creating the Sustainable Finance Council among the principal Spanish sustainable-finance measures.

For Spanish banks, therefore, green finance is no longer simply a voluntary corporate-social-responsibility activity. Environmental considerations increasingly affect disclosure, governance, risk management, lending decisions, investment products, prudential supervision and the information supplied to customers and investors.

2. Regulatory Structure

Spain's green-finance framework can be divided into three interacting levels:

EU level: EU regulations and directives create the principal classification, disclosure, prudential and sustainable-investment framework.

Spanish national level: Spanish legislation establishes climate-transition policies, institutional arrangements and national sustainable-finance objectives.

Supervisory level: Banco de España, the European Central Bank and European supervisory authorities integrate environmental and climate risks into financial supervision.

Consequently, a Spanish bank financing a renewable-energy plant, energy-efficient building or other environmentally marketed project may simultaneously face banking-law, disclosure, taxonomy, governance, consumer-protection and environmental-law requirements.

3. Spanish Sustainable Economy Law

Law 2/2011 of 4 March on Sustainable Economy (Ley 2/2011, de Economía Sostenible) forms an important part of the Spanish legislative background for sustainable economic development.

Banco de España continues to list Law 2/2011 as part of Spain's national sustainable-finance regulatory framework.

The legislation is significant because it helped establish the broader policy connection between:

financial markets;

economic sustainability;

corporate governance;

environmental objectives;

transparency; and

long-term economic development.

For banking law, the central idea is that the financial sector has an important role in allocating capital toward economically and environmentally sustainable activities.

4. Climate Change and Energy Transition Law 7/2021

A particularly important Spanish measure is Law 7/2021 of 20 May on Climate Change and Energy Transition.

Banco de España identifies this legislation expressly within Spain's sustainable-finance framework.

The law connects Spain's climate-transition strategy with the financial system. For financial institutions, climate change can create two major categories of financial risk.

Physical risk

Physical climate events can affect borrowers, collateral and investments.

For example, environmental changes can influence the value of property securing bank loans or affect businesses operating in climate-sensitive industries.

Transition risk

Changes in environmental regulation, technology, consumer preferences and carbon-related policies may reduce the profitability or value of carbon-intensive businesses.

A Spanish bank therefore has to consider whether environmental developments can become ordinary credit, market, operational or concentration risks.

5. EU Taxonomy Regulation

One of the foundations of European green-finance regulation applicable in Spain is the EU Taxonomy framework.

The Taxonomy creates a common classification system for determining when economic activities can be regarded as environmentally sustainable for specified regulatory purposes.

This is particularly important because terms such as “green,” “sustainable” and “environmentally friendly” can otherwise be interpreted differently by banks, investors and companies.

For banking institutions, taxonomy information may affect:

sustainability disclosures;

green financing classifications;

portfolio analysis;

investment products;

corporate lending information;

environmental KPIs; and

Green Asset Ratio calculations.

Thus, merely calling a loan or investment “green” is not enough where a regulatory disclosure requires taxonomy eligibility or alignment.

6. Green Asset Ratio

The Green Asset Ratio (GAR) is particularly relevant to banking regulation.

Under the EU Taxonomy disclosure rules, the GAR indicates the proportion of covered assets of a credit institution that finance or are invested in taxonomy-aligned economic activities.

The applicable framework covers categories such as loans and advances, debt securities and certain equity instruments, subject to regulatory inclusions and exclusions.

In simplified terms:

Green Asset Ratio = Taxonomy-aligned covered assets ÷ Total covered assets

This provides investors and regulators with a standardized indicator rather than relying only on a bank's own description of how “green” its balance sheet is.

The rules have continued to evolve. Amendments applicable in 2026 introduce, among other things, materiality-related provisions for certain assets in taxonomy assessments.

7. Sustainable Finance Disclosure Regulation

The Sustainable Finance Disclosure Regulation (SFDR) is another important part of the EU sustainable-finance system.

It principally concerns financial-market participants and financial advisers rather than functioning as a general rule governing every ordinary bank loan.

Its objective is to improve transparency concerning sustainability matters in financial products and investment decision-making.

The regulatory framework seeks to provide investors with clearer information concerning matters such as sustainability characteristics and sustainability risks.

For banking groups that provide investment or asset-management services, SFDR can therefore become highly relevant.

8. Sustainability Reporting and Bank Lending

Green-finance regulation also depends heavily on corporate sustainability information.

Banks require reliable information about their corporate customers because environmental information can affect:

credit-risk assessment;

taxonomy calculations;

financed-emissions analysis;

transition planning;

collateral assessment;

sector concentration;

regulatory reporting.

This demonstrates an important relationship between corporate sustainability reporting and banking regulation: banks cannot accurately measure environmental exposure if borrowers do not provide sufficiently reliable sustainability information.

Spain is also affected by continuing developments in EU corporate sustainability-reporting legislation.

9. Prudential Banking Regulation and ESG Risk

Environmental risk is increasingly treated as a financial-risk issue rather than simply an ethical concern.

The EU Capital Requirements Regulation remains central to prudential regulation of Spanish credit institutions. Banco de España's current regulatory materials continue to identify Regulation 575/2013 and its subsequent implementing and delegated measures as part of the applicable European banking framework.

For banks, climate-related problems can translate into conventional banking risks.

For example:

Credit risk: A borrower may become less capable of repaying its loan because of environmental regulation or physical climate damage.

Market risk: Securities connected with carbon-intensive industries may lose value.

Operational risk: Extreme environmental events may interrupt bank or customer operations.

Concentration risk: A bank may have excessive exposure to sectors vulnerable to the environmental transition.

Reputational and litigation risk: Misleading sustainability claims may generate regulatory investigations, disputes or investor complaints.

10. Pillar 3 ESG Disclosures

Environmental risk is also relevant under the EU prudential disclosure system.

In June 2026, the European Banking Authority published final draft technical standards updating Pillar 3 ESG-risk disclosure requirements, alongside other disclosure reforms. The EBA explained that these amendments implement CRR3 requirements and seek greater consistency with the broader sustainability-reporting framework.

For Spanish banks falling within the applicable requirements, this means environmental risks increasingly form part of standardized prudential transparency.

Green finance is therefore connected directly with banking supervision rather than existing entirely outside traditional banking law.

11. Green Bonds

Green bonds provide another important source of sustainable financing.

A green bond raises capital for projects or activities connected with environmental objectives. Banks may participate as:

issuers;

investors;

arrangers;

underwriters;

advisers; or

intermediaries.

The European Green Bond framework has created an EU-level regulatory standard for issuers choosing to use the European Green Bond designation.

Its importance lies in establishing more standardized requirements concerning the use of proceeds, disclosure and external review.

Banco de España's sustainable-finance regulatory materials include the European Green Bond framework and subsequent EU measures interpreting and implementing it.

12. ESG Ratings Regulation

Banks and investors often rely on ESG ratings when assessing companies or financial instruments.

However, differences in methodologies and possible conflicts of interest have created concerns about reliability and transparency.

The EU has therefore adopted Regulation (EU) 2024/3005 concerning the transparency and integrity of ESG rating activities.

By 2026, additional delegated regulations had been adopted dealing with matters including ESG-rating disclosures, procedural safeguards and separation of certain rating activities. Banco de España lists these instruments as part of the European sustainable-finance regulatory framework.

This is relevant to Spanish banking because regulated ESG information may influence investment analysis, portfolio construction and sustainable-finance decisions.

13. Greenwashing Risk

Greenwashing occurs when environmental characteristics are presented in a misleading or inadequately substantiated manner.

For a Spanish financial institution, this may arise where:

a financial product is described as sustainable without adequate evidence;

environmental benefits are exaggerated;

significant limitations are hidden;

taxonomy alignment is incorrectly represented;

marketing is inconsistent with contractual documentation; or

sustainability information supplied to investors is inaccurate.

Consequently, greenwashing can intersect with financial-market disclosure rules, consumer law, investor protection and general rules against misleading commercial practices.

Good governance therefore requires sustainability statements to be supported by appropriate data and documentation.

Important Case Laws

A qualification is important here: Spain does not yet have six major final Spanish judgments dealing exclusively with the modern EU Taxonomy/GAR green-banking regime. Much of this regulatory system is comparatively recent. Accordingly, the most useful case law includes EU environmental-finance decisions directly applicable to Spain and related Spanish/EU cases that establish principles relevant to sustainable financing.

1. ClientEarth v European Investment Bank — Case T-9/19 (2021)

This is one of the clearest green-finance cases connected directly with Spain.

The dispute concerned an EIB decision approving financing for a biomass electricity-generation project in Galicia, Spain. ClientEarth requested an internal review of the financing decision under EU environmental-access-to-justice legislation.

The General Court rejected the EIB's restrictive approach and annulled the decision declaring ClientEarth's request inadmissible.

Importance

The judgment demonstrates that a decision made by a financial institution concerning project finance can have a significant environmental-law dimension.

It is especially important for Spanish green finance because the underlying financed project was located in Galicia.

The broader lesson is that environmental requirements cannot necessarily be separated from institutional financing decisions simply because the decision is financial in form.

2. European Investment Bank and Commission v ClientEarth — Joined Cases C-212/21 P and C-223/21 P (2023)

The EIB and European Commission appealed the General Court's judgment.

On 6 July 2023, the Court of Justice dismissed the appeals and confirmed the relevant principles concerning environmental review of the EIB's financing decision.

The Court considered concepts including:

environmental law;

administrative acts;

internal review;

the Aarhus framework; and

the EIB's independence in financial operations.

Importance

This judgment strengthens accountability surrounding environmentally significant financing.

For Spanish banks it is not a judgment directly imposing EIB obligations on ordinary commercial lenders. Its importance is broader: it demonstrates how environmental legal obligations and financial decision-making can intersect.

The underlying dispute again concerned financing of the Spanish biomass project in Galicia.

3. Spain v Commission — Case T-402/06

This General Court case concerned EU financial assistance for environmental infrastructure projects in Catalonia.

The dispute involved Cohesion Fund assistance, public procurement requirements, expenditure eligibility and financial corrections.

The General Court delivered its judgment on 16 September 2013.

Importance

Although this predates today's EU Taxonomy and is not a commercial green-banking case, it illustrates a fundamental principle relevant to green finance:

Environmental objectives do not remove ordinary requirements concerning legality, transparency and proper use of funds.

Green infrastructure projects receiving public or institutional financing must still comply with the legal conditions governing that financing.

For modern sustainable-finance transactions, this principle is relevant to project due diligence and use-of-proceeds controls.

4. Banco Santander — Resolution of Banco Popular III, Case C-687/23 (2025)

The Court of Justice delivered judgment on 11 September 2025 following a reference from Spain's Tribunal Supremo.

The dispute concerned bank-resolution law, capital instruments and investor claims based on allegedly flawed or incorrect information provided in connection with securities.

This was not a green-finance case.

Nevertheless, it is relevant to the legal architecture surrounding green financial instruments because sustainability regulation does not displace fundamental rules governing investor information, securities and bank resolution.

Green-finance relevance

If a bank issues sustainable or green capital-market instruments, environmental labeling does not eliminate ordinary securities-law and banking-law consequences.

Accurate investor information remains essential.

The case therefore helps illustrate the broader proposition that sustainable finance remains subject to the general financial-law framework.

5. Banco Santander v ECB — Case T-610/24 and Appeal C-560/26 P

This litigation concerns Banco Santander and the European Central Bank and therefore belongs to the field of EU banking supervision rather than green finance itself.

In March 2026, the General Court made an order concerning an admissibility objection raised by the ECB. The ECB subsequently brought an appeal, Case C-560/26 P, in May 2026. As of the available 2026 court materials, that appeal is therefore an ongoing proceeding rather than a final merits judgment.

Importance for green-finance regulation

The case is useful mainly for understanding the institutional structure through which EU banking supervisory decisions may become subject to judicial review.

That matters increasingly for ESG regulation because environmental and climate risks are becoming integrated into supervisory reporting and prudential requirements.

It should not, however, be cited as authority establishing substantive Spanish green-finance rules.

6. Commission v Spain — Case C-263/26

This is another current proceeding rather than a final judgment.

The European Commission brought proceedings against Spain on 30 March 2026 concerning Spain's alleged failure to transpose Commission Delegated Directive (EU) 2023/2775, which amended company-size criteria under the Accounting Directive.

The connection with green finance is indirect but important because company-size classifications can affect the scope and operation of EU corporate-reporting requirements, which in turn provide information used within sustainable-finance systems.

Importance

The proceeding illustrates a broader difficulty in EU sustainable-finance regulation:

EU financial and sustainability rules depend not only on regulations directly applicable in Member States but also on timely national implementation of relevant directives.

Because the case is pending, it should be described as litigation concerning alleged non-compliance, not as a final finding that Spain breached EU law.

Relationship Between the Cases

These cases demonstrate different parts of the green-finance legal system.

ClientEarth v EIB and EIB/Commission v ClientEarth are the strongest direct authorities because they involve the financing of an environmentally significant project located in Spain.

Spain v Commission demonstrates financial accountability surrounding environmentally oriented public infrastructure.

Banco Santander/Popular litigation demonstrates that sustainable financial instruments remain embedded within ordinary securities, banking and investor-protection law.

The ongoing Banco Santander v ECB proceedings illustrate judicial control in the European supervisory architecture.

Finally, Commission v Spain (C-263/26) illustrates how implementation of EU corporate-reporting legislation can become relevant to the wider sustainability-information framework.

They should not all be described as “green finance cases” in the narrow sense. Doing so would overstate the existing Spanish jurisprudence.

14. Role of Banco de España

Banco de España has an important role because Spanish credit institutions operate within the national and European supervisory structure.

Its current financial-regulation materials maintain a dedicated sustainable-finance section bringing together relevant Spanish and European measures.

Its broader regulatory database also covers Spanish, autonomous-community and EU financial legislation and provides consolidated regulatory materials for the Spanish financial system.

For banks, environmental regulation therefore operates alongside conventional prudential supervision.

15. Role of the European Central Bank

Significant Spanish banking groups are also affected by the European banking supervisory framework.

Climate-related risks can affect the same financial variables that supervisors traditionally examine: asset quality, collateral values, credit concentrations, business-model sustainability and risk governance.

The practical result is important:

Climate risk is increasingly treated as a financial-risk-management issue, not merely an environmental-policy issue.

Banks consequently need systems capable of identifying, measuring and controlling environmental exposures where those exposures are financially material.

16. Green Lending and Credit Assessment

A Spanish bank providing green financing should normally distinguish between:

Purpose: What will the borrower use the money for?

Eligibility: Does the activity fall within the relevant sustainability classification?

Alignment: Where taxonomy alignment is claimed, does the activity satisfy the applicable criteria?

Environmental safeguards: Are the required environmental conditions satisfied?

Documentation: Does the loan agreement clearly establish the permitted use of funds and relevant reporting obligations?

Monitoring: Can the lender verify how funds are actually used?

This reduces the risk that an ordinary corporate loan is incorrectly marketed or reported as green financing.

17. Governance Responsibilities

Green-finance regulation also affects internal bank governance.

Boards and senior management may need appropriate arrangements for:

climate-risk oversight;

ESG data;

risk appetite;

internal controls;

sustainability disclosures;

product approval;

greenwashing controls;

stress testing;

credit policies; and

regulatory reporting.

Environmental responsibility therefore increasingly moves from a specialist sustainability department into mainstream banking governance.

18. Legal Risks for Spanish Banks

The major legal risks can be summarized as follows:

Disclosure risk — publishing inaccurate sustainability information.

Greenwashing risk — presenting financial products as greener than justified.

Credit risk — failing to account for material environmental risks affecting borrowers.

Regulatory risk — failing to comply with taxonomy, prudential or disclosure requirements.

Litigation risk — challenges by investors, customers or other eligible parties.

Reputational risk — environmental claims conflicting with actual financing practices.

Data risk — relying on incomplete or unreliable ESG information.

Governance risk — inadequate board-level supervision of climate-related financial exposure.

19. Practical Example

Assume a Spanish bank finances a large renewable-energy project.

The bank cannot simply label the transaction a “green loan” and consider the matter finished.

Depending upon the transaction and regulatory context, it may need to determine:

Step 1: whether the financed activity falls within the relevant EU Taxonomy category.

Step 2: whether applicable technical and environmental requirements are satisfied.

Step 3: whether environmental risks could affect the borrower's ability to repay.

Step 4: whether sustainability statements made to investors or customers are properly substantiated.

Step 5: whether the exposure affects regulatory sustainability KPIs or disclosures.

Step 6: whether the borrower must provide continuing environmental information.

Step 7: whether the bank has sufficient evidence and controls to prevent misleading green claims.

Green finance therefore involves both financing environmentally beneficial activity and controlling the financial/legal risks associated with environmental representations.

20. Recent Direction of Regulation

By 2026, the Spanish framework is continuing to develop rather than remaining static.

Banco de España's July 2026 sustainable-finance compilation includes recent EU measures on ESG ratings and European green bonds, alongside Spanish legislation such as Law 7/2021 and the 2025 measure establishing the Sustainable Finance Council.

Similarly, the EBA's June 2026 work on Pillar 3 ESG disclosures demonstrates continuing integration of sustainability information into prudential banking regulation.

Thus, the regulatory direction is toward closer integration of:

environmental classification + corporate information + bank risk management + prudential disclosure + investor protection.

Conclusion

Banking law and green-finance regulation in Spain operate through a multi-layered Spanish and EU framework. Spanish legislation such as the Sustainable Economy Law and Climate Change and Energy Transition Law establishes the national policy and legal foundation, while EU legislation supplies much of the detailed taxonomy, sustainability-disclosure, green-bond and prudential framework.

For banks, the most important development is that environmental issues are increasingly translated into conventional financial-law obligations. Climate change may affect credit risk, market risk, collateral, governance and regulatory disclosure. At the same time, banks must be able to substantiate claims that financial activities or products are environmentally sustainable.

The ClientEarth v EIB litigation is particularly significant for Spain, because it arose from EIB financing of a biomass electricity project in Galicia and established important principles concerning environmental review of institutional financing decisions.

The remaining cases show how sustainable finance interacts with broader rules on public financing, investor information, banking supervision and corporate reporting. Because the modern Taxonomy/GAR/ESG regime is comparatively recent, it is important not to invent six supposedly direct Spanish green-finance precedents where such a body of final case law does not yet exist.

Overall, Spanish green-finance regulation is moving away from treating sustainability as voluntary banking policy and toward treating environmental considerations as part of financial disclosure, governance, risk management, prudential supervision and legal accountability.