What is the DND registry?
The DND registry, formally the National Customer Preference Register (NCPR), is India's national record of how each mobile subscriber wants to be treated by commercial senders. It was set up by TRAI, replaced the older National Do Not Call (NDNC) registry and now works under the TCCCPR 2018 regulations, which record preferences on the operators' shared DLT systems. A preference set with one operator therefore binds every sender on every network.
A subscriber can be fully blocked, which stops all promotional calls and SMS, or partially blocked for categories defined by TRAI, such as banking, insurance and financial products, real estate, education, health, consumer goods and automobiles, communication and entertainment, and tourism. The preference can also be limited to one mode, SMS or voice. It is registered by calling or texting 1909, through the operator's app or website, or through TRAI's DND app, and it can be changed or withdrawn the same way.
The registry restricts promotional communication only. Transactional messages such as OTPs, and service messages tied to an existing relationship, are not blocked by a DND preference, and a service-explicit message backed by consent the subscriber gave the business (recorded on DLT, increasingly through Digital Consent Acquisition) reaches them too. It also differs from an Opt-out: DND is one network-wide setting the subscriber controls with their operator, while an opt-out withdraws consent from one brand. Senders never query the registry themselves; operators apply it automatically in DLT scrubbing.
Key takeaways
- The DND registry (NCPR) is India's national record of each subscriber's preference on promotional calls and SMS, set through 1909, an operator app or TRAI's DND app.
- Subscribers can block all promotional communication or only chosen categories, such as real estate or banking products.
- DND restricts promotional traffic only: OTPs, order updates and other transactional or service messages still arrive.
- Operators enforce it during DLT scrubbing, so a promotional SMS to a blocked number is dropped, not delivered.
- DND is one network-wide setting; an opt-out withdraws consent from one brand. Senders must honour both.
Figure 1
Which SMS reach a DND subscriber?
| No preference | Blocked: other category | Blocked: this category | Fully blocked | |
|---|---|---|---|---|
| Promotional offer | ||||
| Service-explicit, with consent | ||||
| Service-implicit update | ||||
| Transactional OTP |
Hover, tap or arrow-key through the cells — a dot in the corner means there is a note.
Transactional OTP by No preference
DeliveredDelivered
OTPs are never DND-scrubbed. They still need a registered header and template.
Legend — press one to highlight its cells
Row 4 of 4. Transactional OTP × No preference: Delivered. OTPs are never DND-scrubbed. They still need a registered header and template.
How does the DND registry work?
The subscriber sets a preference
By calling or texting 1909, in the operator's app or website, or in TRAI's DND app, the subscriber chooses full blocking or specific categories, and optionally SMS or voice only.
The preference is shared across networks
The operator records it on the shared DLT systems, so every access provider applies the same choice to every sender.
A business sends a promotional SMS
The message goes out under a promotional header and a template whose category is registered on DLT.
Scrubbing compares category and preference
The operator's DLT platform checks the template's category against the recipient's preference and drops the message if that category, or everything, is blocked.
Other categories follow their own rules
Transactional and service-implicit messages skip the DND check. Service-explicit messages pass when a valid consent record exists and stop once the subscriber revokes it.
Violations turn into complaints
A recipient who still gets unwanted commercial messages can complain through 1909 or the DND app. Since the 2025 amendment the window is 7 days, and complaints about unregistered senders no longer need a registered preference.
Example: A Hyderabad developer's project launch
A Hyderabad real-estate developer sends a promotional SMS about a new project to 50,000 past enquirers. Subscribers who fully blocked promotions, or blocked the real-estate category, are scrubbed out before delivery; those who blocked only banking products still receive it. For enquirers who asked for the brochure through the developer's website, the team records consent through the DLT consent process, so a service-explicit message with the brochure link reaches them despite their DND setting. The discount offer itself stays on the promotional template, and customers who opted in to WhatsApp get the launch details there as a marketing template.
Common mistakes with the DND registry
Deleting DND numbers from your records
You don't have to pre-filter, because operators enforce preferences, and deleting DND numbers also loses customers you can reach with transactional or consented messages. Exclude them from promotional sends if your provider bills on submission, but keep the records.
Disguising promotions as service messages
Putting an offer inside a service or transactional template doesn't get past DND: mixed content is treated as promotional, and misuse can cost you the template or the header.
Confusing DND with a brand opt-out
A customer who isn't on DND can still opt out of your messages, and that opt-out must be honoured. Record opt-outs yourself; the registry won't, and the 2025 amendment also bars asking for the same consent again within 90 days of an opt-out.
Assuming DND covers WhatsApp
NCPR governs SMS and voice on Indian networks. WhatsApp has its own opt-in rules and per-user marketing limits: a DND subscriber who opted in on WhatsApp can receive your marketing templates there, and someone who opted out on WhatsApp should not.
Why it matters
Why does the DND registry matter?
For marketers, DND is why a promotional SMS list never reaches everyone: every subscriber whose preference blocks the category is dropped before delivery, and no wording or retry changes that. For compliance teams it marks the line between a legitimate promotion and unsolicited commercial communication. Since TRAI's 2025 amendments, recipients can complain within 7 days, and repeat offenders risk having their telecom resources barred. Knowing what DND does and does not block decides which DLT Message Category a template belongs in, when consent is needed and when WhatsApp, with its own opt-in rules, is the better channel for an offer.
NCPR FAQs
- Does DND block OTP SMS?
- No. DND preferences apply only to promotional communication. OTPs, other transactional messages and service messages tied to an existing relationship are delivered regardless of DND, as long as they use a registered header and template.
- How do I activate DND on my number in India?
- Call or send an SMS to 1909, or use your operator's app or website or TRAI's DND app. You can block all promotional calls and SMS or only chosen categories, and change or withdraw the preference the same way later.
- Can a business check whether a number is on DND?
- Not directly through NCPR; operators apply preferences during DLT scrubbing. Some SMS providers offer a pre-send DND check against their own data, but the operator's check at send time is what decides delivery.
- Can a DND number receive promotional WhatsApp messages?
- Yes, if that person opted in to receive your WhatsApp messages. NCPR preferences are applied by operators to SMS and voice calls; WhatsApp marketing follows Meta's opt-in rules and per-user marketing limits instead.
Best practices for the DND registry
- Register each SMS template under the category that honestly matches its content.
- Capture service-explicit consent through the DLT consent process, not only a checkbox in your own app.
- Keep promotional and service traffic on separate headers so a problem with one never blocks the other.
- Report DND scrub losses as their own line in campaign results so they aren't mistaken for delivery failures.