I recently developed a site that utilized a merchant gateway. I had the gateway in “Test” mode so i could process fake transactions to ensure the system was working properly.
The only fake credit card number I could use was 4111111111111111 which is denoted as a VISA card.
Anyhow, I wanted to make sure I could test with other numbers so I tried putting in random 16 digit numbers. Doing so caused the gateway to return an error, “Invalid Credit Card #”
The reason for this is because the credit card number was not a Mod-10 Credit card number. Mod-10 is used to validate credit card numbers.
Anyhow, here are 2 credit card numbers that you can use for credit card testing when interacting with a payment gateway in test mode:
1. 4111111111111111
2. 4111111111111103
How it verify Mod-10:
1. Take a credit card number and reverse it: 1111111111111114
2. Now multiple each even digit by 2.
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4
_ 2 _ 2 _ 2 _ 2 _ 2 _ 2 _ 2 _ 2
Which is: 2+2+2+2+2+2+2+8 = 22
Note:If any results from your multiples of 2 are 2 digits or greater, then split the digits and add them together
So if 2×6=12 you would add (1+2) not 12
2+2+2+2+ (1 + 2)…
3. Now add the odd digits to 22, 22 + 1 + 1 + 1 +1 +1 +1 + 1 + 1 = 30
4. Now divide by 10
30/10 = 3
Since there is no remainder the card number is Mod-10. If there is a remainder, then the card # is NOT Mod-10
Now with this method you can come up with your own Mod-10 Numbers for testing.
The CVV can be used as 123