To further protect your security, we request your credit card security code each time you checkout, and we do not store this number on our site. Here's where you'll find the requested credit card security codes:   Neiman Marcus Credit Cards Do not require a credit card security code. Visa, Mastercard, Discover & Diner's Club On the back of your card: Three-digit, non-embossed number printed on the signature panel immediately following your account number. American Express On the front of your card: Four-digit, non-embossed number printed above your account number.