Use '1600xx' number series to call customers: RBI to banks

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

Banks and other regulated entities 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. -- PTI