The Telecom Regulatory Authority of India (TRAI) on Friday clarified that phone calls originating from the 1600 number series, which are designated for communications from regulated entities and government bodies to citizens, cannot be blocked, tagged or filtered as spam by any app.
The regulator also stated that promotional calls originating from the 140 number series cannot be tagged or filtered by third-party applications. Such calls can only be blocked through the Do Not Disturb (DND) registry managed by TRAI.
“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 in a statement.
According to the regulator, the 1600 number series was introduced to ensure that important service and transactional communications remain trustworthy and easily identifiable for citizens.
TRAI further explained that the 140 number series is reserved for registered telemarketers making promotional calls.
Customers can block 140 series calls through DND
“The 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 Do Not Disturb (DND) registry,” the regulator said.
Customers who have blocked promotional calls from specific sectors through the DND registry will not receive calls from 140 series numbers associated with those sectors.
“The customer can register his/her DND preference through multiple means including through 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.
The clarification effectively means that users will not be able to label calls from either the 1600 or 140 number series as spam, fraud or any other category through caller identification applications.
Truecaller raises concerns over rising spam
The clarification comes amid concerns raised by caller identification platform Truecaller over a surge in spam calls originating from the 140 and 1600 number series.
According to PTI, Truecaller Chief Executive Officer Rishit Jhunjhunwala said more than 5.1 crore calls from these number series go unanswered every day.
“Specifically with the 1600 series, reserved for service/transaction related calls, we have seen daily blocking actions triple (up by 208 per cent) since October 2025. A total of 7.4 crore (74 million) manual blocking actions have been taken against these series in the past eight months,” Jhunjhunwala said in a social media post.
He added that Truecaller users currently block around 4 lakh calls from the 140 series and nearly 1.25 lakh calls from the 1600 series every day.