Apptivo provides strong integration with various payment gateways. Each gateway provides certain basic features to merchants for free and then charges them for some additional value added services. To allow returning customers to use their saved credit card information on your website, the payment gateway needs to save the credit card info on their side and allow us to access it when your Apptivo powered website is being accessed by a returning customer (client relationship management).
To enable this feature please click on the name of your payment gateway to look at the instructions: