BIN, the first 6 digits of a card, has its own special meaning regardless of the card's network. BIN is an acronym for bank Identification number. The number is utilized for payment approval of a card based transaction whether it is keyed or keyless. With the specific end goal to check for a card validness, BIN lookup is a process of examining such the prefix number of a card on a special BIN database to obtain some sensitive information for validation.
When a user, called XYZ, fills out an application for a card, the financial institute; such as: Wellsfargo, Citi Bank, Chase Bank, etc; would check the user's credit history together with other backgrounds to ultimate determine the application's approval. Once approved, some of the information of the card network company; such as VISA, Mastercard, Amex, etc; and the institute itself are electronically stored in BIN database. This database from the financial institutes will be retrieved to update card processors, third parties databases. One way or another, business owners software will be updated eventually with the new info. Now the business owners have the ability to check user XYZ's card BIN number to ensure of true authentication & authorization.
54435391 MASTERCARD credit United States US BIN List
