USA ePay is a plugin that allows you to accept payment by credit card using your USA ePay account. Securely Accept Credit Cards with USA ePay for WooCommerce. The WooCommerce USA ePay extension provides a completely integrated checkout experience between WooCommerce and USA ePay. Payments take place directly on your website so you have maximum control over what the checkout looks like, and customers never have to leave your site to make a payment.