credit vs debit card algorithm?

[nemonoman]

Does anyone know of a script that determines whether a mastercard or visa card is a Debit card? Just as you can tell it's a master card if the starting 4 digits are between 5100 and 5600, and that it's a Visa card if the first digit is a 4, I assume there's some trick to know the difference between a credit and debit card.

My bank charges extra for debit cards.

[drew010]

this type of information is not available from the number itself. the only information you are able to get from the number is 1) if its a valid luhn 10 number 2) the issuing bank based on the first 6 digits of the card.
you can only tell by the word debit being printed on the card itself.