New Delhi: Caller identification and call management apps such as Truecaller will be prohibited from tagging, blocking or filtering calls originating from certain number series designated by the Telecom Regulatory Authority of India (TRAI) or the Central government for commercial and government communications, under new regulations notified by the telecom regulator.

The amended rules cover numbers beginning with 1600, while consumers will retain the freedom to block or filter calls on their own devices at their discretion.

The Telecom Commercial Communications Customer Preference (Third Amendment) Regulations, 2026 (05 of 2026), also require telecom operators to take action against suspected spammers flagged by their artificial intelligence (AI)-based caller identification systems, even without consumer complaints.

The rules mandate telecom operators to reverify the Know Your Customer (KYC) details of senders identified as spammers and take action against violators, including disconnecting their connections and filing complaints with law enforcement agencies.

According to the notification published on Monday, a telecom operator receiving an incoming call flagged as "suspected spam" by its artificial intelligence or machine learning-enabled system must share details of the call with the originating access provider (OAP) within two hours of identification.

The originating access provider must identify the unique KYC identifiers of the sender associated with the flagged calls within one business day of receiving the information and share those details with other telecom operators.

All operators must then check their networks to determine whether other connections linked to the suspected spammer have been identified in the preceding 10 days.

"If it is found that five or more CLIs (called line identification) of the Sender have been so identified within the last ten days, all the OAPs concerned shall take action against the Sender," the notification said.

15-day suspension for first violation

For a first violation detected through the AI-based system, all outgoing services associated with the sender's telecom resources will be barred for 15 days across all telecom operators, regardless of whether those connections were actually used to make the suspected spam communications.

"For subsequent instances of violations, - (i) all telecom resources, including PRI/SIP trunks, SIMs etc. of the Sender shall be disconnected by all the Access Providers for one year, irrespective of whether those telecom resources were actually used or not in making such communications," the notification said.

The sender will also be blacklisted for one year, during which no telecom operator can provide new telecom resources to the violator.

However, the sender will be allowed to retain one telephone number with outgoing services barred. The connection will be permitted to make calls to notified emergency services.

New rules for promotional calls

The amended regulations also allow terminating access providers (TAPs) to charge originating access providers up to Rs 0.05 per minute, on a per-minute pulse basis, for application-to-person (A2P) calls.

Subscribers who wish to block promotional telemarketing calls across all categories will have to send the text BLOCK PROMO to 1909.

"BLOCK PROMO option shall block only promotional types of Commercial Communications for all categories of content, mode, time band and day types but shall not block transaction and service type of Commercial Communications and Government Communications," the notification said.

Existing preferences registered under the FULLY BLOCK category will be migrated to BLOCK PROMO within 15 days of the notification.

Rules to be implemented in phases

The amended regulations will come into effect one month after the Gazette notification, with implementation taking place in phases over 60 to 90 days.

The provisions related to A2P calling will come into force after 60 days.

Other provisions, including an appeal mechanism through blockchain technology, verification of complaints against data on AI-flagged suspected high-probability unsolicited commercial communication (UCC) senders, and suspension of services for incorrect categorisation of content templates, will take effect after 90 days.