The decision of the department of telecommunications to reject the Telecom regulatory authority of India's proposal for the implementation of portability in mobile services by April 2007 will deprive millions of Indian customers the freedom to choose service providers without changing their phone numbers.

Number portability allows a customer to move from one mobile service to another within GSM, and also between GSM and CDMA, while retaining the same number. It gives flexibility to customers and keeps operators on their toes lest their service quality falls.

According to an IDC survey, over 30 per cent of mobile subscribers would change their operators if they had number portability.

Telecom experts opine that the churn rates, which are around 8 to 10 per cent currently, could virtually double once the portability regime comes into effect.

Telecom operators, which include the Cellular Operators Association of India (COAI), have vehemently opposed the move. And joining the battle are state-owned MTNL [Get Quote] and BSNL, which have so far been lukewarm on the issue. The sole operator which has favoured the move is Tata.

The GSM cellular operators say that implementing portability would require operators to fork out over Rs 4,000 crore (Rs 40 billion), and this would lead to an increase in tariff -- a familiar argument.

Those against the move argue that with a teledensity of around 15 per cent, it is too early to implement portability at such a high cost. And with over 90 per cent of the subscribers in the pre-paid category, the sanctity of the number is less relevant or does not matter.

Those who support portability say the cost has been exaggerated. This cost incurred is nothing compared to the major consumer benefit that it will provide. They say, portability has been implemented globally by the regulators.

Assuming that 15 per cent of the total subscriber base of 200 million by 2007 opts for the service, operators will have to fork out only Rs 900 crore (Rs 9 billion) -- among six operators.

Of course, there is no reason to believe that a part of the cost will not be borne by the customers themselves who should not quibble to pay a small one-time price for the advantage of flexibility.