Typically, credit cards have 16 digits embossed on the front. These digits are exclusive for every card holder and denote the account number of the card.

In a typical sixteen-digit credit card number, the first fifteen digits are determined by the issuing bank. To elaborate, the 2nd through to 6th digits denote the bank number, and the 7th-15th numbers denotes your account number. The remaining digit is known as the check digit. This number is used to determine the authenticity of the overall number and to rule out any duplication or invalid numbers. The check digit is mathematically determined based on all the other digits.