Yes! StudySoup uses a 3rd-party payment processing system via Stripe Payments, a US payment processing company that provides commerce for businesses of all sizes.
StudySoup does not handle any of your personal financial information. No one at StudySoup has access to any financial information that you provide through the site - it goes directly to Stripe. StudySoup is protected under a GoDaddy Secure Server License.
We will never share your personal information with anyone. That's just not cool.