The Department of Telecom has started issuing notices to recover around Rs 863 crore from telecom operators which were found to have allegedly under reported their revenue for period between 2006-08.
"Some notices have gone out. Some are in the process," DoT sources said.
The companies whom the notices are being issued include Bharti Airtel, Vodafone, Reliance Communications, Tata Teleservices and Idea Cellular, they added.
Tata Communications (TCL), which holds an Internet service provider licence, has also figured in list of companies that are accused of under reporting their revenue.
As per earlier calculations done by DoT , sources said, Reliance Communications owes Rs 298 crore and Bharti Airtel Rs 160 crore.
Tata Teleservices, including its subsidiary Tata Teleservices (Maharashtra), may have to pay Rs 142 crore. Vodafone, TCL and Idea Cellular may have to take a hit of Rs 121 crore, Rs 78 crore and Rs 65 crore respectively.
Telecom regulator Trai in 2009 had asked the DoT to conduct a special audit of financial accounts of these five telecom companies for the 2006-08 period observing that operators were under-reporting their revenues to avoid payment of licence fee to the government through revenue share.
The move was to check operators' scope to arbitrage, which is shifting revenue from higher licence fee to the lower side. The UASL (basic and mobile) telephony has a licence fee of 6-10% where as NLD, ILD, ISP and Internet Protocol has six%.
Trai had noticed that some of operators were showing more revenue in segment that carried lower licence fee.
The special audit was for those companies which have multiple licences - Unified Access Service Licence (UASL), National Long Distance (NLD), International Long Distance (ILD) and Internet Service Provider (ISP).