A method (5) and a system 100 are provided for maintaining a self-service terminal (1). The maintenance is effected using a mobile terminal (3), such as a smartphone. A server application that can communicate first via a communication link (23) with a terminal application that is executed on the mobile terminal (3) and second via a network connection (21) with the self-service terminal (1) is executed on a server (2). Direct communication between the mobile terminal (3) and the self-service terminal (1) is not necessary. The mobile terminal (3) uses a still picture production apparatus (31) to capture both an identifier (11) for the self-service terminal (1) and an identifier (121) for a maintained component (12) of the self-service terminal (1), and transmits corresponding data to the server (2). On the basis of this, the server application can ascertain update data and communicate them to the self-service terminal (1).