Telecom Regulatory Authority Of India - Subsection
Section 3(2) in The Telecom Unsolicited Commercial Communications Regulations, 2007
(2)Every call center or any such mechanism set up under sub-regulation (1) shall earmark or allot or establish a specific basic telephone or cellular mobile telephone number having sufficient lines or connections of toll free nature for "customer care number" or "help line number" at every such call center or such mechanism for the purpose of registering the requests of its subscribers for not receiving unsolicited commercial communication and all such calls shall be treated as free calls.
