Convert card numbers to XXXX-XXXX-XXXX-0000 Format XXXX-XXXX-XXXX-4567 NOTE that the 4567 digits shown above relate to the last four digits of the card number This question helps format the string to something like 1234-5678-9123-4567 But it does not help with the format required above While looking for answers I also came across the following solution: