Telecom regulator Trai on Sunday said it has not recommended 11 digit mobile numbers but only suggested prefixing '0' when mobile numbers are called from landlines.

The recommendation on prefixing '0' for calls from fixed line to mobile numbers will generate 2,544 million additional numbering resources for mobile services to cater to the future requirements, it said.

As per Trai recommendation, the country will continue to follow a 10-digit numbering for mobile services, and the regulator has "categorically rejected" shifting to an 11-digit mobile numbering plan.

"Trai has not recommended 11-digit numbering scheme for mobile services," the Telecom Regulatory Authority of India (Trai) said in a statement.

Trai has recommended a dialling prefix '0' while making a call from a fixed line number to mobile number, the statement said, adding that introduction of a dialling prefix for a particular type of call "is not akin to increasing the number of digits in the telephone number".

"This change in dialling pattern will generate 2,544 million additional numbering resources for mobile services to cater to the future requirements," it added.

The regulator on Friday had said that migration to a unified or single numbering scheme for fixed line and mobile services is not required for now and that sufficient numbering space can be created by various methods, including prefixing '0' for all fixed to mobile calls.

Trai while releasing its recommendations on "ensuring adequate numbering resources for fixed line and mobile services" had felt that there needs to be no change in dialing plan for fixed-to-fixed, mobile-to-fixed, and mobile-to-mobile calls.

It has also recommended that a revised and new National Numbering Plan (NNP) should be issued at the earliest, and has made suggestions on ways to free up unutilised capacities, to create space for mobiles services.

During the course of the consultation, most of the operators had opposed 11-digit numbering for mobile numbers, arguing that an 11-digit numbering scheme would incur massive configuration modifications including software and hardware, involve additional cost for the players, and cause confusion and inconvenience to the customers.

"The authority is of the opinion that some serious problems are anticipated with change in the mobile number from 10 digits to 11 digits. This would require widespread modifications in the configuration of switches involving cost.

"This would also cause inconvenience to the customers in the form of dialing extra digit and updating phone memory. This could lead to more dialing errors, infructuous traffic, and loss of revenue to the operator," the regulator had explained in its recommendations.