These cards are equipped with an NFC chip and antenna. When the card is placed (‘tapped’) on a Point of Sales terminal, the terminal sends a handshake signal to the card to initiate a transaction. A unique identification number is generated against the transaction, cross-referenced with the financial institution, and (if validated) the transaction is thereon processed.
Contactless card payment only works when both the units are less than 4 cm apart. These transactions are made over a 13.56 MHz channel, necessitating close proximity between the two units. Moreover, contactless credit and debit cards are designed not to initiate a transaction if the devices are more than 10 cm apart, eliminating any chances of unauthorized access to a user’s data.
As per the guidelines implemented by the Government of India, a cardholder cannot transact more than Rs.2,000 wirelessly without entering his or her ATM PIN. It acts as a safety measure, ensuring no accidental (or unauthorized) payment takes place without the cardholder’s authorization.
EMV contactless card payments can also be made at a conventional POS terminal by swiping or inserting the card in the device. It ensures backward compatibility between the devices so that customers can transact on any platform.