All that will now change with the introduction of MNP. Here is a list of Frequently Asked Questions regarding Mobile Number Portability.
What is Mobile Number Portability?
If you’ve not been updated about this, this service lets you stick to your current number and switch to another operator. For instance, if you are not happy with your current service provider, or if you’re getting a better tariff plan that suits your requirement with another, you can change to that particular provider without having to give up your existing number.
Is it possible to change service operators between circles? For E.g. Move to another city and change to a different operator
Well you can’t do this, at least for now. The Department of Telecom (DoT) has allotted two zones so that all number porting requests don’t overload a single Mobile Clearing House.
Zone I consists of Delhi, Mumbai, Maharashtra, Haryana, Punjab, Gujarat, Rajasthan, Eastern and Western Uttar Pradesh, Himachal Pradesh, and Jammu & Kashmir Licensed Service Areas (LSA).
Zone II includes Kolkata, Tamil Nadu (including Chennai), Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, West Bengal, Assam, Bihar, North East and Orissa LSAs
Because of the configuration of individual Telecom circles, porting can happen between Madhya Pradesh & Chhattisgarh; Bihar & Jharkhand; Rest of West Bengal & Andaman and Nicobar; within the states of the North East except Assam. Apart from these states, you cannot move between any other circle or zone. So if you want to switch operators between