Mobile Number Portability (MNP) for cell phone services in India was introduced from January 2010. What is MNP?. This service allows a subscriber to move from one mobile service provider to another mobile service provider without changing your number (operated in the same licensed service area (LSA)). e.g. if you are a Airtel subscriber, you can switch over to BSNL without changing your mobile number. The new service provider will give you a new sim card. The total charges for this service is Rs.19 and some operators like BSNL have already waived this fees for potential customers.
How to go get portability
Walk in to the new mobile service provider's service centre and fill up the application form for porting and pay the requisite fees.
SMS PORT 10 DIGIT MOBILE NUMBER to 1900 for obtaining UPC(Unique Portal Code). On receipt of the UPC, fill in the application and submit. The porting will be completed within 7 working days except in Jammu & Kashmir, Assam and North Service areas, where it will take around 15 days. There wont be any service for a 2 hour period, which will be communicated. The services with the existing service provider will automatically terminated once the subscriber has ported to the new service provider. Once you have shifted to a new operator, you cannot change over to a new opertor for a period of 90 days.