Hello! Thank you for reaching out. You can update the payment details for your premium care by going on to samsung.com and logging in to the Samsung account associated with the premium care. Once logged in click on where it will say Hi, (your name) and a little menu will come up with the option for my account, select this option. Once on your account page, you are looking for the option to view "My Subscriptions", if you are on the desktop site you will see on the left of your account page a column and the 3rd or 4th option down will be the My subscription tab. If you are logging on using a mobile phone, once on the account page scroll down until you see the option to view my subscriptions. Once on your My Subscriptions page it will show you the premium care accounts associated with that Samsung account. Bellow each subscription will have the option to update payment details. Once filled out and confirmed you should see a grey text bubble pop up saying that the payment was successfully updated. Let me know if this helped!