Despite the widespread adoption of Internet banking there are no validated guidelines on the functionality the younger, techno-savvy Generation-Y customer segment (18-35 year age bracket) expect from Internet banking websites. This research investigated the functionality the Generation-Y customer segment require from South-African Internet banking websites. The User Centred Design (UCD) philosophy with a mixed method research design was utilised. Generation-Y technological characteristics and preferences abstracted from the literature were aligned with functionality trends of future Internet banking websites to formulate an initial list of Generation-Y aligned Internet banking functionality guidelines. These were evaluated during interviews with representative Generation-Y customers and also used in the heuristic evaluation of the Internet banking platforms of five South African banks. The findings were integrated towards synthesizing functionality guidelines. A visual representation of these functionality guidelines was constructed as a wireframe prototype for evaluation by Generation-Y users. The main contribution of the study is the validated list of Internet banking functionality guidelines for Generation-Y banking customers.