TRAI has clarified that no app can block phone calls originating from the 1600 number series, which are reserved for communications by regulated entities and the government to citizens. The regulator asserted its stance amid an ongoing tussle with caller identification app Truecaller over the labelling and identification of calls from this dedicated number series.
TRAI's Stance on 1600 and 140 Series
The Telecom Regulatory Authority of India (TRAI) also clarified that promotional calls originating from the 140 number series cannot be tagged or filtered by an app and can only be blocked by the Do Not Disturb (DND) registry, which is managed by the regulator. “Under the Telecom Commercial Communications Customer Preference Regulation (TCCCPR), any tagging, blocking or filtering of the calls originating from 1600 series numbers is not permitted,” TRAI said.
Purpose of 1600 Series Numbers
The regulator mandated the use of 1600 series numbers for service and transaction calls by regulated entities in banking, financial services, and insurance (regulated by RBI, SEBI, IRDAI, and PFRDA) to their existing customers, and by government entities for government-to-citizen communication. The key objective is to make such calls trustworthy for citizens.
Handling of 140 Series Calls
On calls starting with the 140 number series, TRAI said these are meant for use by registered telemarketers. “Customers have the right to allow or block promotional calls originating from 140 series numbers from entities of any or all sectors by registering their preference on the DND registry,” TRAI said. A customer who has blocked any or all sectors from receiving promotional calls on the DND registry will not receive any calls from 140 series originating from entities of the blocked sectors. The customer can register DND preferences through multiple means, including the TRAI DND App. “Any tagging or filtering of calls from 140 series numbers is not allowed except for blocking on the DND registry, as any tagging can mislead a customer who has otherwise allowed receipt of such calls from a sector on the DND registry,” TRAI added.
Truecaller's Objections
Call management app Truecaller has questioned the regulator’s move, claiming that spammers are abusing the direction. Truecaller CEO Rishit Jhunjhunwala said, “TRAI has issued a press release, reiterating that 1600 and 140 series calls cannot be marked as spam by anyone. This is exactly what is leading to the surge in spam from those series! The data proves without a doubt that spammers are abusing this directive. Why not let us mark numbers from these series as spam if 5.25 lakh people are telling us that it is spam, every single day?”
Regulatory Actions and Data
TRAI has sought authorisation from the Ministry of Electronics and IT to act against apps that violate its norm meant to strengthen the fight against spam and fraud calls. Jhunjhunwala contested TRAI’s approach, stating that the number of spam calls made through the 140/1600 number series skyrocketed, with over 5.1 crore calls from both series going unanswered every single day. Specifically for the 1600 series, daily blocking actions tripled (up by 208%) since October 2025, with a total of 7.4 crore manual blocking actions taken against these series in the past 8 months. He also noted that Truecaller users actively block 4 lakh calls from the 140 series and 1.25 lakh calls from the 1600 series every day.
