HDFC Bank Ltd.

HDFC Bank, the second-largest private sector bank in India, has introduced a system of sending the personal identification number (PIN) for debit card holders through SMS instead of the usual despatch by post. As part of its 'go-green' initiative, the bank wanted to save paper and instead of sending PIN of the debit cards through post it will be send through the SMS.The new PIN issued over SMS is named as ‘Green PIN’. The Green PIN is a one-time password or OTP sent to the customer's mobile number registered with bank. Using the OTP, customers can set debit card PIN at the bank's ATM.

HDFC Bank is one of India’s premier banks providing a wide range of financial products and services to its 28.9 million customers. As of June 30, 2014, the bank had a distribution network with 3,488 branches and 11,426 ATMs in 2,231 cities/towns.