"Our customers can enjoy a superior VoIP calling experience on Airtel's network by choosing from a range of new VoIP specific data packs that will soon be launched. For prepaid users, the VoIP exclusive pack will be priced at Rs.75 for 75MB with a validity of 28 days."

“This will allow customers to make between 200 and 250 minutes of calling. Similarly, affordable VoIP plans will soon be launched for postpaid customers. There would be no other charges in respective of VoIP calls," a company statement said.

The company on its website said: "All internet/data packs or plans (through which customer can avail discounted rates) shall only be valid for Internet browsing and will exclude VoIP (both incoming/ outgoing). VoIP (Voice over Internet Protocol) over data connectivity would be charged at standard data rates of 4p/10 KB [3G service] and 10p/10 KB [2G service]."

"We, therefore, believe that VoIP services in their current form are not tenable for us as a business. As a result, we will charge separately for VoIP services," the company statement said.

However, the company mentioned that the VoIP update is not applicable with immediate effect. This change will be implemented in a phased manner over the next few weeks.

"In all cases, our customers will proactively be informed about these VoIP charges in advance through the company's standard communication channels like SMS, USSD pop-up, email etc."

The statement added: "Prepaid customers who have purchased data plans before Dec 24, 2014 are entitled to use all services opted-for till their packs are consumed or expire, following which, the new terms & conditions on VoIP usage will apply."

Reacting to Airtel's decision of charging its customers extra for VoIP usage, Communications and IT Minister Ravi Shankar Prasad on Thursday said the government will look into it and will come back with structured response.