Telecom regulator says calls from these number series cannot be blocked or filtered

The Telecom Regulatory Authority of India (TRAI) has clarified that phone calls originating from the 1600 and 140 number series cannot be tagged, filtered or blocked by third-party apps, except where blocking is carried out through the regulator's Do Not Disturb (DND) registry for eligible promotional calls.According to a PTI report, the regulator has issued a statement announcing that calls from the 1600 number series are reserved for service and transaction-related communications from regulated entities and government departments, while the 140 series is designated for promotional calls made by registered telemarketers.

What TRAI said about the 1600 and 140 number series

"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.The regulator said it has mandated the use of the 1600 series for service and transaction calls made by banking, financial services and insurance entities regulated by the Reserve Bank of India (RBI), Securities and Exchange Board of India (SEBI), Insurance Regulatory and Development Authority of India (IRDAI) and Pension Fund Regulatory and Development Authority (PFRDA) to their existing customers.

The series is also used by government entities for government-to-citizen communication."The key objective of assigning designated series for these important communications is to make such calls trustworthy for the citizens," the regulator added. For calls originating from the 140 number series, TRAI said the numbers are meant for use by registered telemarketers."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," TRAI said.

The regulator added that customers who have blocked promotional calls from specific sectors through the DND registry will not receive calls from those sectors using 140-series numbers."The customer can register his/her DND preference through multiple means, including through 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 said.

What the clarification means for users

The clarification means users will not be able to tag calls from the 1600 or 140 number series as spam, fraud or any other category using third-party caller identification or spam-filtering apps.The announcement comes after Truecaller CEO Rishit Jhunjhunwala recently said spam calls from the 140 and 1600 number series had increased. He said more than 5.1 crore calls from the two 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 8 months," Jhunjhunwala had said in a recent X post.According to him, Truecaller users currently block around 4 lakh calls from the 140 series and 1.25 lakh calls from the 1600 series every day.