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NDNC/DND Compliance

The National Do Not Call (NDNC) registry, also referred to as DND (Do Not Disturb), is a TRAI-mandated system that allows Indian consumers to opt out of receiving unsolicited commercial communication. Compliance with NDNC is mandatory for all businesses making commercial calls or sending promotional SMS in India.

What is NDNC/DND?​

NDNC is a centralized database maintained by Indian telecom operators where consumers can register their preference to not receive commercial calls and messages. When a consumer registers for DND, their phone number is flagged, and businesses are required to exclude these numbers from promotional communication.

How Consumers Register for DND​

Consumers can register for DND by:

  1. Sending an SMS START DND to 1909 from their mobile
  2. Calling 1909 from their registered number
  3. Using the TRAI DND mobile app
  4. Registering through their telecom operator's website

DND Preference Categories​

Consumers can choose to block all commercial communication or selectively block specific categories:

Category CodeCategoryExamples
0Fully blockedAll commercial communication blocked
1Real EstateProperty listings, construction offers
2EducationCourses, training, admissions
3HealthHealth products, wellness services
4Consumer Goods & AutomobilesProduct offers, vehicle promotions
5Communication / BroadcastingMedia subscriptions, entertainment
6Banking / Insurance / FinancialLoans, insurance, investment offers
7Tourism & LeisureTravel deals, hotel offers

Category-Based Filtering​

If a consumer selects specific categories (e.g., blocks categories 1, 2, and 3), they still receive commercial communication from non-blocked categories (4, 5, 6, 7).

Consumer PreferenceReceives Category 6 (Banking)?Receives Category 1 (Real Estate)?
Fully blocked (0)NoNo
Blocked: 1, 2, 3 onlyYesNo
No DND registeredYesYes

Impact on Exotel Campaigns​

Voice Campaigns​

Campaign TypeDND Impact
Promotional voice callsDND-registered numbers are blocked
Transactional voice callsGenerally allowed (appointment reminders, payment alerts)
Service calls to existing customersAllowed with implicit consent

SMS Campaigns​

SMS RouteDND Impact
Promotional SMS (promo)DND-registered numbers are blocked by the operator
Transactional SMS (trans)Delivered regardless of DND status
Service Implicit (si)Partially affected; depends on category preference
Service Explicit (se)Partially affected; depends on category preference
info

Transactional messages (OTPs, order updates, account alerts) are exempt from DND filtering because they are considered essential communications, not commercial solicitations. However, you must not abuse the transactional route for promotional content.

How Exotel Handles DND Filtering​

Automatic DND Filtering​

Exotel integrates with the NDNC database and provides DND filtering at multiple stages:

  1. At contact upload: Numbers can be checked against the NDNC registry when uploaded to a contact list
  2. At campaign execution: Numbers are filtered in real time before calls are placed or SMS are sent
  3. In reporting: DND-filtered contacts are flagged in campaign reports

DND Filtering in Campaign Reports​

DND-filtered contacts appear in your campaign reports with specific status codes:

StatusDescription
dnd_filteredNumber is on the NDNC registry; call/SMS was not attempted
dnd_category_blockedNumber has blocked the specific communication category

Scrubbing Your Contact Lists​

Before running a promotional campaign, scrub your contact list against the NDNC registry:

Pre-Campaign DND Check​

  1. Upload your contact list to Exotel
  2. Exotel automatically checks numbers against the NDNC database
  3. DND numbers are flagged in the upload report
  4. When the campaign runs, flagged numbers are automatically skipped

DND Scrub Freshness​

The NDNC registry is updated regularly. Numbers can be added to or removed from DND at any time:

ConsiderationRecommendation
DND registrations take effectWithin 7 days of consumer request
DND deregistrations take effectWithin 7 days of consumer request
List freshnessRe-scrub contact lists that are more than 7 days old
tip

For recurring campaigns, re-scrub your contact list before each campaign run. A number that was not on DND last week may have been registered since then.

Handling DND Complaints​

If a consumer files a DND complaint against your communication:

Complaint Process​

  1. Consumer files a complaint through their operator or the TRAI DND app
  2. The operator investigates and may contact Exotel
  3. Exotel forwards the complaint details to your account
  4. You must respond with evidence of consent or compliance within the stipulated timeframe

Protecting Your Account​

PracticeHow
Maintain consent recordsKeep records of when and how each contact provided consent
Use correct campaign typesEnsure transactional content uses transactional routes only
Honor opt-out requestsProcess unsubscribe requests promptly
Monitor complaint ratesTrack DND complaints in your account dashboard
Document everythingStore consent timestamps, communication logs, and opt-out records
warning

A high volume of DND complaints can result in your Sender ID being blacklisted, your ExoPhones being suspended, or financial penalties from TRAI. Take every complaint seriously and maintain thorough consent documentation.

DND Exemptions​

Certain types of communication are exempt from DND filtering:

Exempt CommunicationCondition
Transactional messagesMust be genuinely transactional (OTPs, alerts, updates)
Government communicationsAuthorized government notifications
Emergency servicesPublic safety and emergency alerts
Existing customer serviceCommunication related to an existing business relationship (with implicit consent)
warning

Misusing transactional routes to send promotional content is a serious violation. Telecom operators monitor for this and may blacklist your Entity ID or Sender ID if promotional content is detected on transactional routes.

Best Practices for DND Compliance​

  1. Always set the correct campaign type: Use promo for promotional and trans for transactional
  2. Pre-scrub contact lists: Filter DND numbers before every campaign
  3. Maintain consent records: Document explicit consent with timestamps
  4. Provide opt-out mechanisms: Include unsubscribe instructions in promotional SMS
  5. Monitor DND complaint rates: Review complaints regularly in your dashboard
  6. Train your team: Ensure marketing and sales teams understand DND obligations
  7. Audit regularly: Periodic compliance audits prevent violations

Frequently Asked Questions​

Can I call a DND number if the person is my existing customer?​

You can make service-related calls (transactional) to existing customers even if they are on DND. However, you cannot make promotional calls. The communication must be directly related to your existing business relationship.

How quickly does DND registration take effect?​

DND registration typically takes effect within 7 days of the consumer's request. During this transition period, the number may still receive commercial communication.

Can a consumer unregister from DND?​

Yes. Consumers can deactivate DND by sending STOP DND to 1909 or through the TRAI DND app. Deactivation also takes up to 7 days.

Does DND apply to WhatsApp messages?​

TRAI's DND regulations primarily apply to traditional SMS and voice calls through telecom operators. WhatsApp Business messages follow Meta's own policies and are not directly subject to NDNC filtering. However, WhatsApp has its own anti-spam measures.