PSD2 is the second EU Payments Services Directive. It will lead to big changes in EU banking. Most recent regulations have harmonised EU payments. PSD2 is different. The changes are radical and it is breaking new ground. Information from a customer's payment account is very useful. It is a vital ingredient for developing financial products. For many years, only the bank providing the account had this information. If more providers get this information, innovation and competition will increase. PSD2 cracks open this information for all providers. PSD2 lets many service providers initiate payments and access data from an account. The customer needs to agree to this. Payments experts are not the only people impacted by PSD2. Product designers, risk managers, consultants, compliance officers, investors and bank customers should understand PSD2. This book explains PSD2 to business professionals who are not payments experts. It shows how payments data could be a key ingredient in new service innovations. It explains how the business models of traditional banks could change. PSD2 in Plain English avoids the jargon used by payments experts. The book carries the accreditation of a 'Plain English Book Mark'. This accreditation means the book's clarity has been independently assessed by the Plain English Campaign. The Book Mark requires clear layout and design. The language in the book is appropriate for the intended audience.