The Internet of Things (IoT) refers to a network of computers, mechanical gadgets, and electronic sensors that can exchange data with one another and work together automatically to complete tasks. In an IoT system, a "Thing" can be any living being, machine, or inanimate thing that is being tracked by a sensor network. These sensors collect data, which is subsequently sent through a network to be processed and put to good use. The term "Internet of Things" refers to the interconnection of devices integrated in many different systems. Because they have a digital representation, these gadgets and things may be communicated with and controlled from a distance. This level of interconnectivity allows us to gather information in previously inaccessible settings, which boosts the reliability and safety of our day-to-day operations. This project details the planning and execution of an Ultrasonic Sensor and Arduino UNO-based BAC detection and engine-locking system for automobiles. If the level of alcohol detected by the sensor rises above a predetermined threshold, the system will cut power to the vehicle's engine. Additionally, the model will communicate the vehicle's location using SIM900A. The project offers a practical means of preventing drunk driving accidents