If you are in the market, I wrote a set of FoxPro modules for Windows/Dos that interface nicely with IC VERIFY in a multi-user LAN setup. The great folks at _IC_VERIFY_ are the original source of this data, I only formatted it in HTML. Note: Card is valid because the 70/10 yields no remainder. Step 3: Sum = 70 : Card number is validated Step 3: The total obtained in Step 2 must be a number ending in zero (30, 40, 50, etc.) for the account number to be validated.įor example, to validate the primary account number 49927398716:
Step 2: Add the individual digits comprising the products obtained in Step 1 to each of the unaffected digits in the original number. Step 1: Double the value of alternate digits of the primary account number beginning with the second digit from the right (the first right–hand digit is the check digit.) The following steps are required to validate the primary account number: LUHN Formula (Mod 10) for Validation of Primary Account Number Here is a table outlining the major credit cards that you might want to validate.Ģ.
When issuing cards, say an affinity card, you might want to add a check digit using the MOD 10 method.ġ.Prefix, Length, and Check Digit Criteria When a user has keyed in a credit card number (or scanned it) and you want to validate it before sending it our for debit authorization. By running the algorithm, and comparing the check digit you get from the algorithm with the check digit encoded with the credit card number, you can verify that you have correctly read all of the digits and that they make a valid combination. A simple algorithm is applied to the other digits of the number which yields the check digit.
A check digit is a digit added to a number (either at the end or the beginning) that validates the authenticity of the number. Most credit card numbers are encoded with a “Check Digit”. This document outlines procedures and algorithms for Verifying the accuracy and validity of credit card numbers.