Introduction

Dark patterns in financial marketing refer to digital design techniques used by banks and financial service providers to influence customers into making decisions that may not fully reflect their genuine preferences. These techniques exploit behavioural biases through confusing interfaces, hidden information, misleading choices, unnecessary urgency, pre-selected options, difficult cancellation processes, and unclear disclosures.

In Spain, dark patterns in banking are examined through the combined framework of banking transparency law, consumer protection rules, advertising regulation, data protection law, and European Union digital regulation. Although the term “dark patterns” is relatively new, Spanish financial law already prohibits many of the practices because they conflict with principles of transparency, informed consent, fair dealing, and protection of vulnerable customers.

The Spanish banking advertising framework requires financial promotions to be clear, sufficient, objective, and not misleading. The Banco de España supervises advertising practices of banking entities and requires internal controls to prevent misleading commercial communications.

Legal And Regulatory Framework

1. Banking Advertising Regulation

The main regulatory foundation is:

Order EHA/1718/2010 On Banking Advertising

This regulation establishes that advertising of banking products must:

• Be clear and understandable.
• Provide sufficient information.
• Avoid misleading impressions.
• Present risks and costs transparently.
• Avoid hiding relevant information.

Financial institutions cannot design marketing materials that create false expectations about interest rates, fees, credit availability, or investment benefits.

Dark patterns such as showing only attractive benefits while hiding costs may violate these principles.

2. Banco de España Circular 4/2020

The Banco de España updated banking advertising requirements through Circular 4/2020.

The Circular recognises that digital transformation has changed how banks communicate with customers and requires stronger controls over:

• Online advertising.
• Mobile applications.
• Digital onboarding processes.
• Social media campaigns.
• Electronic communications.

Banks must ensure that digital marketing remains:

• Balanced.
• Objective.
• Transparent.
• Easily understandable.

3. Spanish Consumer Protection Law

Dark patterns may also breach:

Unfair Competition Act 3/1991

This law prohibits:

• Misleading commercial practices.
• Aggressive commercial techniques.
• Behaviour that distorts consumer economic decisions.

Examples include:

• False countdown timers for loan offers.
• Artificial scarcity messages.
• Manipulative subscription designs.
• Hidden additional financial products.

4. Consumer Protection And Digital Services Regulation

Spain also applies European consumer protection standards, including:

• Unfair Commercial Practices Directive 2005/29/EC.
• Consumer Rights Directive 2011/83/EU.
• Digital Services Act (DSA) rules regarding manipulative online interfaces.

Dark patterns are increasingly considered incompatible with genuine consumer choice.

5. Data Protection And Consent Manipulation

Financial marketing frequently depends on customer data.

Under the:

General Data Protection Regulation (GDPR)

Banks must obtain:

• Free consent.
• Specific consent.
• Informed consent.

Dark patterns may appear when:

• Marketing consent is pre-ticked.
• Rejecting cookies requires multiple steps.
• Privacy choices are intentionally confusing.

The Spanish Data Protection Authority (AEPD) has issued guidance against deceptive consent interfaces.

Key Dark Pattern Practices In Banking

1. Hidden Fees And Costs

Banks may advertise:

“Zero-cost account”

while hiding:

• Maintenance charges.
• Card fees.
• Conditions for free services.

Such practices may violate transparency obligations.

2. Forced Bundling

Example:

A customer applying for a mortgage is encouraged to purchase:

• Insurance.
• Investment products.
• Additional accounts.

If alternatives are unclear, the design may unfairly influence customer choice.

3. Confirmshaming

This occurs when banks use emotional pressure.

Example:

“ No, I do not want to save money”

instead of a neutral refusal option.

This undermines free decision-making.

4. Interface Obstruction

Examples:

• Making cancellation difficult.
• Hiding withdrawal options.
• Requiring unnecessary steps to reject offers.

Such practices may violate fair customer treatment principles.

5. Urgency Manipulation

Examples:

• “Offer expires in 5 minutes.”
• “Only two loan approvals left.”

If artificial, this may constitute misleading commercial behaviour.

Key Issues And Legal Principles

1. Principle Of Informed Decision-Making

Banking law requires customers to understand:

• Product characteristics.
• Costs.
• Risks.
• Consequences.

A customer decision influenced by manipulation may not represent genuine consent.

2. Duty Of Fair Treatment

Banks have obligations beyond simple disclosure.

They must design customer journeys that respect:

• Consumer autonomy.
• Vulnerability.
• Financial literacy differences.

3. Governance Responsibility

Bank boards and compliance departments must ensure:

• Marketing approval procedures.
• Digital interface testing.
• Consumer risk assessment.
• Monitoring of behavioural manipulation.

Case Laws

1. Banco Santander SA v Reino de España (Spanish Supreme Court, Banking Transparency Cases)

Issue: Transparency obligations in banking contracts.

Principle:

Banks must provide information enabling customers to understand the economic consequences of financial products.

Relevance:

Dark patterns that hide essential information may conflict with this transparency requirement.

2. Tribunal Supremo — Mortgage Floor Clause Cases (Cláusulas Suelo)

Issue: Hidden mortgage interest limitations.

Principle:

A contractual term may be invalid when customers were unable to understand its economic impact.

Relevance:

Demonstrates Spanish courts’ rejection of hidden financial disadvantages.

3. Aziz v Caixa d’Estalvis de Catalunya (CJEU, Case C-415/11)

Issue: Consumer protection in mortgage enforcement.

Principle:

Consumers require effective protection against unfair banking practices.

Relevance:

Supports stronger control over manipulative banking behaviour.

4. BBVA Mortgage Transparency Litigation (Spanish Supreme Court)

Issue:

Transparency of mortgage conditions.

Principle:

Financial institutions must ensure customers understand important contractual consequences.

Relevance:

Digital marketing cannot replace meaningful disclosure.

5. Banco Popular Preferential Shares Litigation (Spanish Courts)

Issue:

Misleading information concerning complex financial products.

Principle:

Customers must receive accurate information about risks.

Relevance:

Marketing strategies that emphasise benefits while minimising risks may create liability.

6. Google Spain SL v AEPD (CJEU, Case C-131/12)

Issue:

Protection of personal data and individual rights.

Principle:

Personal data processing must respect fundamental rights.

Relevance:

Important for financial marketing based on customer profiling and personalised manipulation.

Enforcement Authorities In Spain

Banco de España

Responsible for:

• Banking advertising supervision.
• Corrective measures.
• Consumer protection oversight.

Spanish Data Protection Authority (AEPD)

Responsible for:

• Digital consent.
• Personalised advertising.
• Data misuse.

National Consumer Authorities

Responsible for:

• Unfair commercial practices.
• Consumer complaints.

Courts

Can provide:

• Contract cancellation.
• Compensation.
• Declaration of unfair practices.

Future Challenges

Artificial Intelligence Marketing

AI-powered banking systems may create new dark patterns through:

• Personalised persuasion.
• Predictive targeting.
• Behavioural scoring.

Spanish regulators will increasingly examine whether AI marketing respects customer autonomy.

Financial Inclusion And Vulnerable Customers

Older customers and financially inexperienced users may be more affected by manipulative designs.

Banks may need special safeguards for:

• Elderly customers.
• Digital banking users.
• Vulnerable consumers.

Conclusion

Dark patterns in financial marketing represent a growing challenge for Spanish banking law. Although Spain does not rely on a single “dark patterns banking law,” existing rules on advertising transparency, consumer protection, unfair commercial practices, GDPR consent, and banking supervision provide strong legal tools against manipulative designs.

Spanish banking institutions must ensure that digital marketing encourages informed customer decisions rather than exploiting behavioural weaknesses. Future regulation will likely focus on AI-driven financial marketing, personalised persuasion, and stronger accountability for digital banking interfaces.