You may allow your customers | students to safely save credit cards in ASAP for future use. A checkbox to "Save this card" is offered in the Payment page of the Public page (customer facing) and Admin page invoice, to add convenience and ease of checking out for future purchases, if customer would like to use the saved card in the future (Similar to Amazon). They are asked for a nickname for the card.
To turn this on, go to Configure | Preferences and under the section called Payment and Transaction Configuration, click Edit and check the box "Use Saved Credit Cards".
What this does: it allows office staff to store cards on the account as well as your customers / students to elect to save a card on their profile. This is an option for each student and not a requirement.
To save a card on Admin side, go to the customer Family Account page, scroll to bottom of the page, and click "Add a new card". The customer may go to their My Account page, click the "My Billing Info" tab, click "Add a new card."
NOTE: Two features, the Automated Recurring Billing (ARB) feature and the Payment Plan feature for invoices, do not require this "Use Saved Credit Cards" preference to be YES. ARB and Payment plan payments will still capture, save and auto-charge a credit card that was used to purchase initial or subsequent invoice associated with the enrollment, even if no cards are saved in the system using "Save this card" feature. But if this preference is off, and if customers or Administrators need to add a new credit card to an account for a registrant of an ARB class or payment plan, they will need to enable this preference temporarily, add the card, configure the card for the enrollment, then disable the preference. The ARB and Payment plan features will still operate correctly with the single enrollment associated to the card, the but card is otherwise not available as a saved card for other purchases.