A Mobile or landline subscriber who does not wish to receive telemarketing calls, can request their telephone number be included in the NDNC Registry. Such request are sent through their telecom service providers which will be stored in National Do Not Call Registry.Subscribers can make a Do Not Call requests via Letter, phone, SMS or on-line.The telephone number "1909" is designated for registering your request in the National Do Not Call Registry. Registrations can be done either by calling or sending SMS with keywords "START DND" to "1909". Telephone calls/SMSs to this number are FREE of cost. The telecom service provider will acknowledge the request within ten days. Requests will become effective in 45 days from the date of request.