New Delhi, July 12 -- The Telecom Regulatory Authority of India (TRAI) has issued a clarification on the purpose and functioning of the designated 1600 and 140 number series.

The regulator said these two series serve completely different purposes. While 1600-series numbers are reserved for service and transaction-related communications, 140-series numbers are exclusively meant for promotional or marketing calls.

The 1600-series is meant for service and transaction calls made by banks and financial institutions to their existing customers, along with government-to-citizen communications.

These numbers can only be used by entities in the BFSI sector that are regulated by the Reserve Bank of India (RBI), Securities and Exchange Board of I...