Mobile users will not need to buy a new SIM while changing service provider or buying a new connection, according to new guidelines issued by the Department of Telecom to allow use of embedded SIMs (eSIM). The eSIM will be installed in the device and details of service providers can be updated in it at the time a customer buys a new connection or changes operator or wants to buy standalone service from a telecom operator like data or calling etc. "To cater the needs of modern technological developments in M2M\/IoT, it has been decided to permit the use of "Embedded-Subscriber Identity Module (eSIM) with both single and multiple profile configurations with over the air subscription update facility, as the case may be, as per prevailing global specifications and standards," the DoT said. The guidelines have been issued five days after Reliance Jio and Bharti Airtel started selling Apple Watch Series 3 which has eSIM service. Users of Apple Watch Series 3 can connect their eSIM with SIM in their mobile and use the service that are being provided on their mobile phone by Jio or Airtel on their smartwatch. The DoT has allowed profile updation over the air to facilitate mobile number portability on eSIM and avoid locking of device by a telecom operator. The DoT has directed telecom operators facilitating service on eSIM that it is their responsibility to meet lawful interception and monitoring requirement as well as ensure that manufacturer of the device does not tamper with eSIM. Along with guidelines for eSIM, the DoT issued instructions for SIMs that will be used for machine-to-machine communications like alert sent from car to mobile over low fuel, faulty parts, car theft, remote surveillance of premises, smartmeters etc. The department has earlier issued direction that all SIMs for M2M communications will come with 13-digit number. Since the number of SIMs required for M2M communications will be huge, the DoT has enhanced number of connections per user to 18 which includes 9 SIMs that can be used for normal mobile phone communications or for use in devices which has slot for them. The other 9 SIMs can be purchased for M2M communications. According to the guidelines, in case where M2M are required to be pre-installed in devices, it will be responsibility of device makers to complete subscriber verification. However, it will be responsibility of the person or end user to update subscriber details if he or she transfers device to other user.