Can’t Block Calls From 1600 Number Series, But Can Put 140 Series on DND: TRAI

The Telecom Regulatory Authority of India (TRAI) has issued a strict directive stating that no caller ID or spam-blocking application is permitted to block, tag, or filter phone calls originating from the 1600 number series.

According to the regulatory body, the 1600 series is strictly exempt from spam classification because it is not meant for general promotional calls. Instead, these numbers are exclusively allocated to government agencies, banks, insurance companies, and financial institutions to communicate critical service updates and transaction-related information to their existing consumers. TRAI emphasized that special regulatory protection has been granted to the 1600 series to ensure that citizens maintain complete trust in these essential communications. Conversely, the regulator clarified that the 140 number series remains explicitly designated for registered telemarketing and promotional campaigns.

Navigating DND Rules and Rising Spam Concerns
For users wishing to avoid promotional calls originating from the 140 series, the only officially authorized method is to register their preferences through the national Do Not Disturb (DND) registry. TRAI clarified that it is against regulations for third-party apps to independently filter or tag 140 numbers as fraudulent or spam. The regulator explained that app-based filtering could create confusion, potentially flagging legitimately permitted promotional calls—which users may have explicitly opted into—as malicious spam.

However, caller identification giant Truecaller has expressed significant concerns over the growing volume of spam originating from both the 140 and 1600 prefixes. Truecaller CEO Rishit Jhunjhunwala highlighted that consumers are actively ignoring over 5.1 crore calls from these two series every single day. Furthermore, platform data indicates that Truecaller users are manually blocking approximately 4 lakh calls from the 140 series and 1.25 lakh calls from the 1600 series daily. Despite these massive figures and clear user frustration, TRAI’s stringent guidelines mandate that third-party applications cannot automate the blocking or spam-tagging of the essential 1600 series under any circumstances.