Mumbai, Jan 17 (PTI) The RBI on Friday asked banks to use only the ‘1600xx’ phone numbering series to call customers for transactional purposes with a view to preventing financial fraud.

It further said that for promotional purposes, banks and other regulated entities (REs) should use only the '140xx' numbering series for the prevention of financial frauds perpetrated using voice calls and SMS.

Banks and other regulated entities (REs) have also been asked to monitor and clean their customer database.

The proliferation of digital transactions, while offering convenience and efficiency, has also led to a surge in frauds, a pressing concern underscoring the need for concerted action, said a Reserve Bank circular to REs.

The mobile number of a customer has emerged as a ubiquitous identifier, instrumental in the account authentication and verification process, receiving sensitive payment communication, such as OTPs, transaction alerts, and account updates.

"The mobile number, however, can also be misused by scamsters in multiple ways for committing various types of online and other frauds," the circular said on 'Prevention of financial frauds perpetrated using voice calls and SMS – Regulatory prescriptions and Institutional Safeguards'.

"Undertake transactional / service calls only using ‘1600xx’ numbering series, when operationalised; undertake promotional voice calls only through phone numbers using '140xx' numbering series; follow the 'Important Guidelines for sending commercial communication using telecom resources through Voice Calls or SMS' issued by Telecom Regulatory Authority of India (TRAI)," it said.

The RBI asked the REs to utilise the Mobile Number Revocation List (MNRL) available on the Digital Intelligence Platform (DIP) developed by the Department of Telecommunications (DoT) and the Ministry of Communications to monitor and clean their customer database.

To enhance fraud risk monitoring and prevention, the REs have been asked to develop Standard Operating Procedures (SOP) incorporating the required action to be taken.

The required action to be taken includes updating the registered mobile number(RMN) after due verification, and enhanced monitoring of accounts linked to these revoked mobile numbers to prevent the linked accounts from being operated as Money Mules and/or being involved in cyber frauds, the circular said.

The Reserve Bank has asked all the REs to ensure compliance with the instructions expeditiously, in any case, not later than March 31, 2025. PTI NKD CS NKD BAL BAL

Transactional call numbering: banks must use 1600xx series for customer transactions to curb voice and SMS fraud. REs must use the 1600xx series for transactional/service calls and the 140xx series for promotional calls, follow TRAI commercial communication guidelines, utilise the Mobile Number Revocation List on the Digital Intelligence Platform to clean customer databases, develop SOPs for fraud-risk monitoring, verify and update registered mobile numbers, and apply enhanced monitoring to accounts linked to revoked numbers to prevent misuse; compliance is required by March 31, 2025.