Adding multiple credit/debit cards can be done by following the same steps for adding a credit/debit card.
Note: The first credit/debit card you add is automatically marked as the default payment method. When you add an additional card, you can make that the default payment option instead if you like.
You can change your default card at any time from the Payment Methods tab by clicking the kebab (three-dot) menu for that card and choosing Set as default in the dropdown menu.
We will always charge your default card if possible. The additional card(s) may be used if we are unable to charge your primary card for some reason.