At the beginning of the 21st century, the holistic consideration of the customer and their value contribution has increasingly come to the forefront of bank management. This has led to a high relevance of customer value controlling, which supports customer value management by creating an adequate information base for assessing the value contribution of individual customers or the entire customer segment. Around the same time, the demands on external accounting also increased, which has been required to adopt a more investor-friendly accounting approach since the introduction of International Financial Reporting Standards (IFRS). Although the IFRS initially only pertain to external financial reporting, they are characterized by a close integration with controlling instruments. This is particularly evident through the mandatory application of the "Management Approach.".