Credit Card Glossary: Terms and Definitions
		Confused by credit card terms? CreditCards.com's glossary of credit card definitions will help. From account holder to Regulation Z, we have defined the most-common and most-confusing credit card terms.

Issuer identification number (IIN)

If you look at a credit card's numbers, the digits are divided into two parts. The first six digits are the issuer identification number. When you make a purchase with a credit card, the processing system first looks at the first six digits, which identify the issuer. The remaining digits identify your specific account.