Seren developed a style guide for GSM Association for the operation of mobile payment mechanisms in retail outlets.  The GSM Association wanted guidelines to deliver an optimal customer experience to be used by operating companies around the world. Seren directed a number of workshops to identify personas, typical scenarios, use-cases and service touch-points.  From these a skeleton description of the service was mapped out and defined.  Seren then focused on the mobile channel and designed the user interface of the payment experience, covering every aspect of the service.