Trai clarifies: No app can block 1600 series calls; 140 series can be blocked via DND

The Telecom Regulatory Authority of India (Trai) on Friday clarified that no application can block phone calls originating from the 1600 number series, which are designated for communications by regulated entities and government agencies to citizens. Promotional calls from the 140 series, however, can be blocked using the Do Not Disturb (DND) registry, but these cannot be tagged or filtered by any app.

Under the Telecom Commercial Communications Customer Preference Regulation, any tagging, blocking, or filtering of calls from the 1600 series is not permitted, Trai stated. The regulator has mandated the use of 1600 series numbers for service and transaction calls by regulated entities — including those in banking, financial services, and insurance regulated by RBI, Sebi, IRDAI, and PFRDA — to their existing customers, as well as for government-to-citizen communication. This measure aims to make such calls trustworthy for citizens.

The 140 number series is intended for use by registered telemarketers. Customers have the right to allow or block promotional calls from these numbers by registering their preference on the DND registry. However, any tagging or filtering of calls from the 140 series is not allowed except for blocking on the DND registry, as such tagging could mislead customers who have otherwise allowed receipt of such calls from a particular sector.

This implies that users will not be able to tag calls from numbers starting with 1600 or the 140 series as spam, fraud, or any other category using third-party apps. Truecaller CEO Rishit Jhunjhunwala has reported that the volume of spam calls from these series has surged, with over 5.1 crore calls from both series going unanswered daily. He noted that Truecaller users currently block 4 lakh calls from the 140 series and 1.25 lakh calls from the 1600 series each day.

The regulation underscores the balance between enabling legitimate communications and protecting consumers from unsolicited calls, while preventing mislabeling that could undermine trust in official channels.