To remove your card on an iPhone 6 or later, select “Remove Card” in the “Wallet & Apple Pay” section of your device “Settings” or on the back of your Card in the Wallet app. You can also visit icloud.com/settings to remove your card or Find My iPhone to temporarily suspend or permanently remove the ability to pay with your Cards on your device.
To remove your card on Apple Watch, go to "Wallet" on your Apple Watch device, select your card then hold and tap "Delete" to remove your card. Additionally, you can remove your card using the Apple Watch app on your iPhone. Open the Apple Watch app, select "Wallet & Apple Pay", then select your card and navigate to the bottom and tap "Remove card." Please note that you can always visit icloud.com/settings to remove your card on Apple Watch.