The 2CheckOut payment gateway allows you to receive one-time and recurring payments, issue refunds, and other features.
AsiaPay is an online payment service and solutions provider in Asia that provides electronic payment gateway solutions.
The Echeck module for Authorize.net allows you to process payments directly from a bank account.
The BidPay payment gateway module is available in WHMCS.
The BitPay payment gateway module allows you to accept Bitcoin payments.
Boleto is a payment gateway in WHMCS.
The CashU payment gateway module is available in WHMCS.