Open banking allows users to access financial information and services through consent-based data portability. This paper brings together the views of private and public experts from a wide variety of countries to explore opportunities and challenges of open banking for financial regulation, privacy protection, and competition. It discusses the different approaches taken by jurisdictions across the globe, and the importance of regulation and standards. While open banking empowers users in sharing and re-using their data across digital services, online platforms, sectors and borders, uncertainty in the interactions with data protection and privacy regimes remains challenging. This paper informs OECD work to consider how cross-sectoral cooperation between financial, competition and data protection authorities could help further open banking.