We have prepared a video tutorial for this section @ http://www.whmcs.com/tutorials.php?i=3
Payment gateways can be setup in Config > Payment Gateways. Each gateway has it’s own specific data requirements in order to process transactions so they will vary from gateway to gateway. However, all gateways have 3 core fields:
The following is a list of the payment gateways that are supported.
Gateways often have test modes where you can use test card numbers. The common test card numbers are below and should generate successful test transactions but they can vary from gateway to gateway. You may use any expiration date in the future.
4007000000027 - Visa Test Card 4012888818888 - Visa Test Card II 5424000000000015 - MasterCard Test Card 370000000000002 - American Express Test Card 6011000000000012 - Discover Test Card 3088000000000017 - JCB Test Card (Use expiration date 0905) 38000000000006 - Diners Club/Carte Blanche Test (Use expiration date 0905)