The European Payments Council (EPC) Quick Response (QR) code is a technical standard by the European Payments Council. It uses a QR code containing all the necessary information for initiating a SEPA credit transfer (SCT). It is commonly used on invoices and payment requests in the countries that support it (Austria, Belgium, Finland, Germany, The Netherlands).
The EPC guidelines are available from the EPC itself. Another version has also been published by the Federation of Finnish Finance Services (FFI).