We process payments using a third-party called Authorize.net. You can learn more aout them here. They are one of the leading payment processing companies in the world and have extremely high levels of security.
We never handle your credit card data on our servers and all payments are processed on Authorize.net's site for your security and peace-of-mind. When you arrive to our checkout page in the design tool, you will click a button that will redirect you to Authorize.net's payment page that will redirect you back to our site when you finish your payment.
The only data that we store of yours is your email address, first name, last name, phone number, and design information. We do not store any other personal information on our servers for security reasons.