The first 4 digits of the card determines the type of card it is and who issued it.
Preauthorisation reserves funds from the card holders credit limit. If the authorisation is not completed this reservation eventually expires and the reserved funds are released back to the credit limit. Sometimes a pre-auth is done for mail order goods at the time of purchase to ensure funds are available and then the full auth and settlement done once goods are despatched. On 2/28/06, Jim McAtee <[EMAIL PROTECTED]> wrote: > > Two questions, probably unrelated: > > To an online merchant, is there any way to tell a debit card from a credit > card of the same type (VISA, MasterCard, etc.) just from the card number? > > I've dealt with some companies (Verizon comes to mind) that run some kind > of preauthorization against a credit card before running the actual charge > transaction immediately afterward. What is the reasoning behind doing > this? > -- Mike T Blog http://www.socialpoints.com/ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Message: http://www.houseoffusion.com/lists.cfm/link=i:4:233623 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/4 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:4 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=89.70.4 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
