A backseat child occupancy safety alert system. More specifically, the invention relates to a system that can be used in any vehicle and includes a plurality of sensors that cover the seat belt buckles of a vehicle to detect the motion of the seat belt buckle within the seat belt housing. Each sensor is in electrical communication and powered by a tether that allows one sensor to communicate to the other or a display via a flashing LED screen and audible tone if a child is still buckled into the rear vehicle seat after a user attempts to exit the vehicle via the driver's seat. The system is powered continuously by a USB or other power outlet in the vehicle. A kit for retrofitting a vehicle with the system and method of installing the system are also provided.