If you're attempting to process a payment via the WHMCS admin area and it is being rejected, but succeeds when paying via the client area with the same card details, this may be due to an issue with the WHMCS admin area. We are aware of an issue with WHMCS where the CVV code entered via the admin area (when processing a payment) is having any leading zeroes stripped away and causing payments to fail with the following error being logged to the Billing > Gateway Log page:
errorCode => 5021
errorName => Invalid CVV2 Value
errorMessage => The value for the CVV2 (ssl_cvv2cvc2) field should either be 3 or 4 digits in length. This value must be Numeric.
This appears to affect all current versions of WHMCS and has been reported to WHMCS. In the meantime, using the Login as Owner option to process such payments via the client area, or leaving out the CVV when trying to process via the admin area, appears to work.
