The first digit of your credit card number is the Major Industry Identifier (MII), which represents the category of entity which issued your credit card. Different MII digits represent the following issuer categories:
| MII Digit Value | Issuer Category |
|---|---|
| 0 | ISO/TC 68 and other industry assignments |
| 1 | Airlines |
| 2 | Airlines and other industry assignments |
| 3 | Travel and entertainment |
| 4 | Banking and financial |
| 5 | Banking and financial |
| 6 | Merchandizing and banking |
| 7 | Petroleum |
| 8 | Telecommunications and other industry assignments |
| 9 | National assignment |
For example, American Express, Diner's Club, and Carte Blanche are in the travel and entertainment category, VISA, MasterCard, and Discover are in the banking and financial category, and SUN Oil and Exxon are in the petroleum category.