MUMBAI: The Reserve Bank of India on Thursday said that banks can allow contactless card transactions upto Rs 2,000 without PIN authentication . The move is seen boosting `tap and pay' electronic transactions at retail outlets and toll booths. `Tap and pay' refers to the use of nearfield communication (NFC) technology , which enables holders of `contactless cards' to make payments by waving or tapping the card near the card reader.Prior to this relaxation, after tapping the card at a point of sale machine, the cardholder had to punch in a PIN number as an additional factor authentication. Earlier in the day, SBI , had launched its sbiINTOUCH contactless card on 5,000 point of sale machines.According to the central bank, lenders should give customers the choice to set a limit lower than Rs 2,000 per transaction. It has also said that authorisation of `contactless payment' will be the responsibility of the issuing bank. The central bankhas also said that contactless cards should be chip cards that adhere to EMV payment standards.It has asked banks conduct velocity checks to decide on how many such small value transactions can be allowed in a day or a week or even over a month.