This probably does not affect most merchants but if your credit card terminal tests the first 4 digits to determine the card type, you might need a software enhancement. What is happening? The BIN makes up the first 6-digits of any card number. MasterCard previously issued cards with BINs beginning with 5. From 14 October 2016, MasterCard will start issuing additional card numbers with the BIN Range of 222100-272099. Will this affect me? If you have a website or systems that validate that a MasterCard begins with 5, you will need to update your website and/or systems to allow the new BIN range. When will it happen? MasterCard have announced that the New 2 Series BIN range will be effective on 14 October 2016.