MII Info:
0 – ISO/TC 68 and other industry assignments
1 – Airlines
2 – Airlines, financial and other future industry assignments
3 – Travel and entertainment
4 – Banking and financial
5 – Banking and financial
6 – Merchandising and banking/financial
7 – Petroleum and other future industry assignments
8 – Healthcare, telecommunications and other future industry assignments
9 – For assignment by national standards bodies
| Card Type | Starts with | Length |
|---|---|---|
| American Express | '34'or'37' | '15' |
| Diners Club and Carte Blance | '30','36' or '38' | '14' |
| Discover | '6' | '16' |
| Master | '5' | '16' |
| Visa | '4' | '13' or '16' |
Source - https://www.creditcardinsider.com/learn/anatomy-of-a-credit-card/