Mobile phone subscribers may soon be allowed to switch from a postpaid connection to prepaid and vice versa by using an OTP-based authentication and without a need to change SIM card, according to an official DoT note. Industry body Cellular Operators' Association of India (COAI) has proposed the mechanism to the Department of Telecom (DoT) and the department has asked telecom operators to carry out proof of concept (PoC) on the same. The final decision on allowing the change in the account will depend on the outcome of PoC, according to the DoT note. "The PoC for conversion from prepaid to postpaid and vice versa may be carried out by the telecom service providers as per the procedure...The decision regarding implementation of the procedure shall be taken after the assessment of the outcome of the PoC," DoT ADG Suresh Kumar said in the note issued on May 21.