The coupling of data and digital innovation opens the way for new business in the financial services sector, where customers are placed at the centre of decisions and data can help to develop customer knowledge. To carry out our research, we adopted a multi-case study approach to explore how a data strategy is developed in the retail banking industry, together with its relationship with customer value, paying particular attention to the heterogeneity between traditional banks and financial technology companies (FinTechs). Two main points emerged from the study. Firstly, there are three possible approaches to Open Finance, which are mainly defined by their different corporate cultures, organisational configurations, technological architecture and data value. Secondly, it is not enough to be a FinTech to be best placed to exploit the market, as some traditional banks share the FinTechs’ approach to Open Finance. Designing new tailored products, customising their prices and offering them over the right channels through targeted communication are all data-driven initiatives that stem from cross- or up-selling potential, core to the retail banking industry for turning a customer into a cash flow, thus enabling value to be created for customers. Our findings additionally revealed that there is a form of external information asymmetry between the customer and the bank, and that there is also an internal asymmetry between bank departments, as their visibility on information about the same customer may differ.