In the Philippines, one of the solutions to energy theft from utilities involves the relocation of electric meters to elevated metering centers, away from the residential building. The length of the service conductorshad made it vulnerable to illegal connections. The proposed solution is a system with theft recognition and magnitude determination mechanisms. The two mechanisms work based on voltage and energyreadings. The system was designed and tested using a residential building-rated microcontroller-based prototype utilizing an energy monitor as input device and the ZigBeeprotocol for wireless communication. The sensitivity, specificity, and success rate of the recognition mechanism were all 100 percent. The percent error of the theft magnitude determination mechanism ranged from 0 to 2.17 percent. Through cost-benefit analysis, the system was found to have positive net benefit at theft probabilities higher than 3.94 percent. The system has excellent usability as assessed though System Usability Scale.