How does one determine that the card a person is entering is a debit card, check card, or credit card?
I am looking at this for web payments in the US only. This is for utility billing.
I'm thinking you are getting confused that when you swipe the card in a store the machine knows which kind of card you've got. Although with my Dutch debit card I always got the option to choose..
But I'm guessing the magnetic strip stores more than just the number, and the card readers use that to determine your type of card.
You'll just have to join the other applications/sites and ask the user :)