All of the numbers on a credit card have a meaning. Packed into the 15- or 16-digit sequence of major credit cards are the credit company, the identifying bank number, your account number and security fraud codes. By identifying the credit company from the number, small business owners will know the service charge for that transaction. To find the credit company of a particular card, just look at the first two numbers.
Step 1
Identify a bank card's credit company by looking at the first number. Cards that start with a "3" are American Express. Those that start with "4" are Visa credit and debit cards, those that start with "5" are MasterCard credit and debit cards, and those that start with "6" are Discover credit cards. The service fee that is charged to merchants varies between card companies.
Step 2
Count the digits in the credit card number. Most credit cards should contain either 15 or 16 digits. American Express credit cards contain 15. The other three major credit companies -- Visa, Mastercard and Discover -- have a 16-digit sequence on their cards.
Step 3
Look at the first number on the card again to determine the industry within which the card was issued. Along with identifying the credit company, the first number on the card serves as the major Industry Identifier, which tells you if it is a bank or gasoline card, for example. Cards that start with 1 and 2 are issued by airlines, those beginning with 3, such as American Express, are identified with travel and entertainment, numbers 4, 5 and 6 are bank cards, and those that start with 7 are issued by gasoline companies, such as ExxonMobil and Chevron.