The Payson payment gateway module is available in WHMCS.
Planet Authorize is a credit card merchant gateway that is integrated with WHMCS.
The PSIGate payment gateway module is available in WHMCS.
Quantum Gateway supports 3D Secure for Visa® and MasterCard® transactions.
Quantum Vault is the remote storage version of Quantum Gateway.
The SagePay payment gateway module works with both US-based and UK-based accounts.
SagePay Form sends your customers to the Sagepay website to enter payment details.