DND

Telecom operators run it under TRAI’s TCCCPR 2018. The choices subscribers make are recorded in the national preference register, the NCPR.

How it works

Under TCCCPR 2018 (PDF), opens in a new tab, every operator must offer a free preference facility round the clock. A subscriber can register or change a preference by:

• sending an SMS to 1909, or calling 1909 and following the IVR;
• dialling a USSD code;
• using an approved mobile app, such as TRAI’s DND app, or a web portal with OTP login.

The regulation requires the preference to take effect within 24 hours. The main choices are “block promo”, which blocks all promotional communication, and blocking by category. There are eight categories, and real estate is category 2, so an SMS reading “BLOCK 2” to 1909 blocks real estate promotions only.

Blocking promotions does not stop transactional or service communication, such as a bank alert or a delivery update, or government communication. Under the 2025 amendment (PDF), opens in a new tab, a promotional call still reaches a DND subscriber if the sender holds the subscriber’s explicit digital consent recorded under the regulations.

As of September 2026 there is also a stricter “fully block” option, but not for long. The Third Amendment (PDF), opens in a new tab removes it in its first stage, which comes into force 30 days after the amendment is published in the Gazette. From that date, operators have fifteen days to move every “fully block” preference to “block promo”.

Why it matters for sales teams

A real estate lead list will contain numbers that have blocked promotional calls, and calling them from a sales campaign invites complaints to the operator. Complaints count against the sender, and TRAI’s 2025 changes (PDF), opens in a new tab made action faster: a customer has seven days to complain, and five complaints in ten days trigger action.

Removing those numbers before dialling is scrubbing, done through the business’s registered telemarketer on DLT. It is a registration-backed step, not something a calling tool can do on its own.

Example

A buyer in Noida sent “BLOCK 2” to 1909 years ago. Now she fills in a portal form about a 3 BHK project. Her enquiry is not the same as consent recorded in the DLT consent register, so when the developer’s telemarketer scrubs a promotional campaign list, her number is removed unless such consent has been registered.

Common confusions

• DND vs NCPR. DND is the facility and the everyday name; the NCPR is the register where the preferences are kept. TRAI itself uses both, as in its July 2026 clarification (PDF), opens in a new tab that refers to the “Do Not Disturb (DND) registry”.
• DND vs a company’s own opt-out list. When someone tells one business to stop calling, that business should record it on its own suppression list. That is separate from DND, which covers all senders in a category.
• DND vs spam-blocking apps. Caller ID apps label numbers by their own methods. TRAI’s July 2026 clarification says calls from the 140 series may be blocked only through the DND registry, not tagged or filtered by other means.

This entry is a summary as of September 2026, not legal advice.