Question

Show that 4128 0012 4389 0110 is an invalid VISA number card

Answer 1

visa cards begin with 4 and then have 13 or 16 digits but here we have a number beginning with 4 and then it has the 15 digits.

Explanation:

1. Each card has a different first digit number. The maximum length of this type of credit card number can be up to 19 digits.
2. In the visa card starting 6 digits are always said to be the issuer identifier.
3. The visa cards will have the starting digits as 4 whereas in Mastercard the starting digit is 5 but it has 16 digits numbers.