How to Stop Promotional Calls & SMS

Stop Unsolicited Calls from Airtel

To stop telemarketing calls from Airtel send SMS START DND to 1909 or use this form. For Landline users, you need to register your phone number using this form
Stop Telemarketing Calls from Vodafone

To avoid unwanted telemarketing calls, register your Vodafone number in NDNC Registry – call 1909 (toll tree) or sms START DND on 1909 (toll free). And in case you want to de-register yourself from the NDNC registry sms STOP DND to 1909 (toll free).
Stop Telemarketing Calls from Idea Cellular

Should you desire to stop receiving such communication from Idea, all you need to do is to fill the form. The fine print say they require 30 working days to remove your number from the telemarketing lists.
Block Unsolicited Calls from MTNL

The MTNL Delhi service takes you to fill a form on the Unified Call Center web Portal which asks for your LandLine / CDMA / GSM No. or Customer Account No.
Block Telemarketing Calls from Reliance Mobile

If you do not wish to be informed about new features, products and promotional offer through telephone calls or by SMS, you can unsubscribe from such communication by filling up this form.