In this paper, the authors explain based on using MikroTik router Operating System (OS) to build an authentication and billing System. This kind of system is always used to create security, billing and administration of users on a network connected to the internet. It is used to restrict usage and bandwidth allocations to users. A case study of Federal University of Technology, Minna website was considered and it was found that additional stages and radius server services should be incorporated with the antenna design in its hotspot server.