Artificial Intelligence (AI) is reshaping banking by improving credit assessments, fraud detection, and risk management. Many financial institutions are adopting sophisticated machine learning models because they often outperform traditional statistical models in predicting customer behaviour.
However, some of the most powerful AI systems operate as “black boxes” producing decisions without clearly explaining how they arrived at them.
While this may be acceptable in some industries, it presents a serious governance challenge in banking, where transparency, accountability, and fairness are essential.
A black box model makes predictions using complex algorithms that are difficult for humans to interpret. Unlike traditional credit scoring models, where risk managers can identify how factors such as income, repayment history, or debt levels influenced a lending decision, black box models provide little insight into the reasoning behind their outputs. This lack of explainability makes it difficult for institutions to justify decisions to customers, regulators, auditors, and boards.
Governance in banking requires that significant decisions can be understood, challenged, and defended. If a customer is declined for a loan, the institution should be able to explain why. Likewise, regulators expect banks to demonstrate that AI-driven decisions are fair, consistent, and compliant with applicable regulations. When these explanations cannot be provided, governance standards are weakened.
One of the greatest risks associated with black box models is accountability. Although AI can automate decision-making, responsibility remains with the bank’s management and board. Executives cannot simply attribute lending outcomes to an algorithm. They must understand how AI systems operate and ensure appropriate oversight throughout the model lifecycle.
Another major concern is bias. AI models learn from historical data, which may contain unintended biases. Without transparency, it becomes difficult to detect whether certain customer groups are being treated unfairly. Explainability is therefore essential for identifying and mitigating discriminatory outcomes before they become systemic risks.
Black box models also create challenges for model risk management. Economic conditions change, customer behaviour evolves, and model performance can deteriorate over time. Institutions need to understand why a model’s performance changes in order to take corrective action. If the underlying logic remains hidden, monitoring and validation become significantly more difficult.
Importantly, accuracy alone should never determine whether an AI model is suitable for banking. An algorithm that predicts defaults more accurately but cannot be explained may introduce greater governance, legal, and reputational risks than a slightly less accurate but transparent alternative. Responsible AI requires balancing predictive performance with explainability, fairness, and regulatory compliance.
Fortunately, explainability and innovation are not mutually exclusive. Banks can adopt Explainable AI (XAI) techniques, implement independent model validation, conduct fairness testing, monitor model performance continuously, and maintain human oversight for high-impact decisions. These practices enable institutions to benefit from AI while preserving strong governance standards.
Boards also have a critical role to play. Rather than asking only whether an AI model is accurate, they should ask whether its decisions can be explained, whether bias has been assessed, who is accountable for outcomes, and how ongoing performance is monitored. These questions move AI governance from a technical discussion to a strategic boardroom responsibility.
AI will continue to transform banking, but trust remains the foundation of financial services. Customers, regulators, and shareholders expect decisions that are not only accurate but also transparent, fair, and accountable. Black box models challenge these expectations by obscuring the reasoning behind decisions that have significant financial consequences.
The future of AI in banking will not belong to the most complex models. It will belong to the models that institutions can understand, govern, and trust. Explainability is no longer simply a technical advantage it is a governance imperative.
Writer is Daniel Arhin, ACIB – Manager, Lending at Standard Bank Offshore (Isle of Man, UK), with 15+ of experience across lending, credit risk, investment banking, governance, and data science. He is also a Council Member of the Chartered Institute of Bankers.