To update or change your credit card information you need to sign into your KrowdFit account using a browser. Changing credit card information is not supported in the mobile app. After you sign into your KrowdFit account navigate to Settings > Subscription where you will find the "Change Card" button in the "Payment Method" section. Complete the process there and the credit card will be updated going forward. If you have any past due invoices those will be collected at that time, but your renewal date will not change.