Hi, does any one know the number of alphanumeric characters for the following credit card numbers. I was assuming 16 characters for all of them, but am not so sure anymore. Visa, Mastercard, American Express, Discover Thanks! Harlow Pinson Indepth Learning Email: hpinson at indepthl.com Web: http://www.indepthl.com Voice: 505-255-8085 FAX: 505-255-8084