Automatic Teller Machines (ATMs) are still one of the most used customer service channels for bank customers. In that sense, the last years, there has been a tendency to increase the range of operations available and implement them on ATM apps. However, it is observed that several of these new features are not used by customers. It is reported that customers do not use them because they do not know them or because they are difficult to use. Therefore, the challenge has been raised of taking an existing functionality of the ATM app and redesigning the user interfaces and the screen flow by applying principles of Usability and User Experience, as well as applying concepts related to HCI, under an UCD approach. Likewise, security aspects have also been taken into consideration, which implies interacting with an ATM. This case study was carried out in the context of a HCI course of the Master in Computer Science of the PUCP University in collaboration with the ATM team of BBVA Peru. There were three meetings between the PUCP student teams and the Bank specialists. In the first meeting, the problem related to ATM functionality was enunciated, in the second meeting the elaborated prototypes were shown, in the last meeting the final prototype was presented with the adjustments obtained after the user evaluation applied. The feedback received was very positive both by the students of the HCI course and by the Bank specialists regarding the improvement of the User Experience in general.