Improvement
Customer Portal
Payment Methods modal gives subscribers one screen to manage every card on their account, with the primary and the backup labeled so there's no guessing which card is paying for the subscription.
Until now, confirming which card was primary and setting a new backup meant moving between screens, and a subscriber halfway through an update could remove the card funding their next order. Now it's one modal. Set a primary, set a backup, add a new card, or swap which is which, all from the same place, and the primary card is protected from accidental removal. Every action on that screen is one a subscriber would want to take. Nothing else is in the way. This matters most on the cards you never hear about. A subscriber whose card is about to expire and who bounces off a confusing update flow doesn't email you. They fail to bill and churn quietly a cycle later.
Fewer dead ends on that screen means fewer of those. The primary card can't be deleted outright, only replaced. If a subscriber wants it off the account, they set the new one as primary first.
