Telecom operator Uninor today said it has started refunding unutilised money of its prepaid customers in Mumbai and helping them to transfer their numbers to other service providers.

The development follows telecom regulator Trai directing Uninor to refund within 15 days the balance amount of its subscribers in Mumbai and Kolkata, where the company has closed down its operations.

"With this directive now out, Uninor will immediately begin offering porting codes to its Mumbai subscribers. Additionally, the company had already started the balance refund process at five of its stores in Mumbai," the company said in a statement.

On February 15, the Supreme Court had directed that the "entire" licences quashed by it for 2G spectrum be auctioned without "further delay" and those telecom firms which were unsuccessful and did not participate in the auction process will cease to operate "forthwith".

Uninor is majority owned by the Norway-based Telenor Group. Telenor is in the process of transferring the business of Uninor in 6 circles to new entity Telewings Communications, which recently won spectrum in fresh auction.

Porting Authorisation Code (PAC) is a unique identifier used by a few mobile network operators to facilitate mobile number portability (MNP). This allows users to retain their mobile telephone number when switching operators.

"While most of our subscribers in Kolkata have already ported out, Uninor will open up MNP facilities for the remaining interested subscribers shortly," the company said in the statement.

"Since we had already put the entire process in place while awaiting approvals for launch, Uninor can start providing MNP codes to customers (Mumbai subscribers) immediately," Uninor Managing Director Sigve Brekke said in the statement.

"Refunding unutilised balance, though a daunting exercise, is also the right thing to do – the very least we can for our customers affected by this sudden Court ordered closure in Mumbai," the company's Managing Director said.

Uninor has 10,12,630 customers in Mumbai and Kolkata.