1. The Framework - How Spain Defines Design Justice

A. Ley 7/2020 for Digital Transformation of Financial System
Created the Spanish FinTech Sandbox. It allows innovative projects to be tested under supervision of Banco de España, CNMV and DGSFP. Objectives: risk minimisation, mitigation of regulatory burden, boost open innovation. This is the controlled testing pillar - design must be tested with real vulnerable users before scaling.

B. Ley 15/2022 Integral for Equal Treatment and Non-Discrimination
This is the legal backbone of design justice. Entered into force 14 July 2022. Article 2 says no person can be discriminated against on grounds of birth, racial or ethnic origin, sex, religion, age, disability, sexual orientation, health condition, language, etc. regardless of nationality or residency status.

Article 17 specifically: Right to equal treatment in the offer to the public of goods and services. This directly applies to fintech apps, lending algorithms, onboarding UX.

The Spanish Constitutional Court dismissed the unconstitutionality appeal against this law in 2024, confirming its full validity.

C. Law 11/2023 on Digital Accessibility + Law 8/2021 + PSD2
These are cited as the 7 pillars of inclusive finance in Spain. PSD2 was transposed in 2019 regulating Payment Initiation and Account Information Services, mandating open APIs and strengthening identification.

D. EU AI Act + Spanish AESIA
Credit scoring is explicitly classified as High-Risk under Annex III point 5(b). Spain launched regulatory sandboxes under AESIA supervision for AI testing without sanctioning risk.
Obligations: explainability, bias mitigation, human oversight. Original deadline was 2 Aug 2026, now deferred to 2 Dec 2027 by Digital Omnibus, but AI literacy duty is in force since Feb 2025.

2. What Design Justice Means in Practice for Spanish FinTech

Anti-Discriminatory Design: Financial algorithms that use AI must be designed to avoid discrimination and bias. Abogacía Española warns: programs that decide under criteria not necessarily equitable become arbitrary, incurring discrimination, hence law proposes algorithmic responsibility.

Explainability & Transparency: Transparency of algorithms and explainability of decisions are fundamental to ensure rights.

Accessibility by Design: Ley 11/2023 forces apps to be usable by elderly and disabled - not an optional feature.

3. Key Case Laws in Spain

A. The Revolving Credit Usury Jurisprudence - FinTech Lending Model on Trial
This is the most important fintech design justice case law in Spain.

STS 149/2020 (4 March 2020): Supreme Court declared a 26.82% APR on revolving credit null for usury. It established that interest rates higher than 20% for deferred payment constitutes usury.

STS 258/2023 & STS 154/2023 (15 Feb 2023): The First Chamber definitively set the differential: revolving is usurious if it exceeds the Banco de España average by more than 6 percentage points. The Court referred to Banco de España Statistical Bulletin Chapter 19.4, noting APRs were often higher than 20% and even exceeding 23-26%. Consequence: nullity is radical, absolute and original.

Design Justice Lesson: FinTech BNPL, neobanks like WiZink, Cetelem, etc. that designed revolving UX with small installments hiding total cost were struck down. Transparency control now requires contract to clearly state it is an indefinite loan.

B. Algorithmic Discrimination Cases - AEPD

AEPD PS/00291/2019 and AN 0000104/2021: Spanish Data Protection Agency sanctions on controllers for customer acquisition and marketing using opaque profiling. STS 551/2023 ruled indemnity from processor does not apply to controller's own breach.

General Doctrine: Under Law 15/2022, legal presumptions shift burden of proof - if statistical bias shown, company must prove algorithm not discriminatory. Consequences of AI discrimination apply even without AI Regulation fully approved.

C. PSD2 and Access to Account - Banco de España FinTech Cases
406 Spanish fintech firms studied 2014-2022 show open banking under PSD2 disrupted market. Cases where banks blocked FinTech access to APIs were held abusive. Design justice requires XS2A (Access to Account) must be non-discriminatory.

D. STS 2109/2019 - Crypto as Money
Supreme Court ruled Bitcoin does not meet criteria of electronic money under Law 21/2011 on Electronic Money. Protects consumers from misleading design that presents crypto as legal tender.

4. How to Apply Design Justice in Your FinTech (Spain Checklist)

1. Bias Audit: Before launch, run Article 10 EU AI Act audit for datasets - gender, age, postcode proxies.
2. Transparency Layer: Provide plain-language explanation of credit denial under Art 22 GDPR + Ley 15/2022 Art 17.
3. Usury Stress Test: Compare your APR vs Banco de España average +6pp rule from STS 154/2023.
4. Sandbox Application: File via Law 7/2020 to Banco de España innovation hub - mandatory for high-risk AI.
5. Accessibility: WCAG 2.1 AA compliance for Ley 11/2023.