System and method for management and optimization of waiting time for check-out service by using an unique identifier recognition via local wi-fi network with the purpose to manage one or several check-out positions (cashiers or counters), optimizing waiting time for check-out service. This system and method is designed to be used by persons, where each individual is identified by the unique physical address identifier (such as the MAC address) of their personal mobile device with Wi-Fi connection. To access the system on the local server, the user must connect to the licensed establishment's exclusive Wi-Fi local network and access the system using a dedicated pre-installed application or URL address, according to the user's choice. It is therefore a system designed to optimize waiting time, where the addition of new users will occur by mobile device (such as smartphones, tablets, iPods, netbooks, notebooks or other similar devices).