Credit Card checksums and validations that do not require connection to the financial institution
- by cjavapro
The validations I know of are:
Checksum the whole card number should add up to zero. (range is 0-9)
Check the first digit(s) against the card type
Check the length against the card type
Check the CCV length against the card type (I think all the major types are 3 anyway)
Of course make sure it is accepted card type as well as non expired.
Are there any other validations :) (I expect many folks did not know about all of these)
The reason I ask is because I overheard there was one to checksum number against expiration or CCV.. I just wanted to check.