A declined renewal card gets three weeks of grace
When a member’s auto-renewal card is declined, Stripe tries it again over the following days and the member is emailed once, with a link to update their card. They stay a member for up to 21 days past their renewal date while that happens, and the admin home lists them under Waiting for you (the Renewal Declined tab on People), in case a personal nudge would help. If the card is never fixed, the membership lapses and they’re told how to renew. You don’t need to do anything for any of this to happen.