A lock is an integral part of every house. A man can have peace of mind only when he has a proper mechanism to lock his house when he is away. At present mechanical locks are being used. These locks have levers in them that are used to lock or unlock the unit. Keys that have a particular pattern of cuts and notches on them control these levers. Each lock opens only if the pattern of cuts and notches inside it match with the pattern on the key. The Electronic number lock has four main parts- a DTMF keypad, a set of thumbwheel switches, a logic circuit and an electromagnetic locking mechanism. The keypad is installed outside the house along with a switch for opening the lock (‘Open’) and a switch for clearing the memory (‘Clear/Lock’). The thumbwheel switches, logic circuit and the electromagnetic locking mechanism are installed inside the house. Two switches – one for opening the lock and another for clearing the memory are also installed inside. The user can set the three-digit code number using the thumbwheel switches.