Apple takes security pretty seriously, particularly when it comes to Apple Pay, and authentication features like Touch ID and Wrist Detection help to ensure that only you can use your device to make payments. However, if you’ve misplaced your iPhone or Apple Watch, you may not be entirely confident in relying solely on these features to protect your credit cards or bank accounts, so Apple provides several ways to remove your Apple Pay information from these devices even when they’re not in your hands.
If you’ve lost your iPhone, iPad, or iPod touch, and you’re concerned that it may be in somebody else’s hands, the best thing to do is to immediately put it into Lost Mode by logging into your iCloud account at iCloud.com, selecting Find My iPhone from any web browser, and then clicking on your iPhone and choosing the “Lost Mode” option. This will not only immediately suspend all Apple Pay credit and debit cards associated with that device, but will also disable Touch ID entirely, and allow you to enter a message that can be displayed on the home screen along with a phone number that whoever finds your iPhone can call you at by tapping on a link. When your iPhone or other iOS device is back in your hands, you can unlock it with your normal passcode or password and then enter your Apple ID password when prompted to turn off Lost Mode and re-enable your Apple Pay cards. Note that this does not affect your ability to use your actual physical credit or debit cards; only the virtual cards associated with Apple Pay on that specific iOS device are suspended.
If you’d rather permanently deactivate any Apple Pay cards associated with your device, or you’re dealing with an Apple Watch, where “Lost Mode” isn’t currently supported, then you can remove your Apple Pay cards entirely from the Settings section in your iCloud account. In here you should see a list of all of your devices, with those enabled for Apple Pay showing the Pay logo beside them. Click on a device, and you’ll see the list of Apple Pay cards associated with that device, with “Remove” links beside each. Simply click on these and they’re removed. The Apple Pay virtual card number will be deactivated on the back-end processing systems, so this even works with the Apple Watch or an iPhone that’s offline, and as with suspending cards in Lost Mode, this only affects the virtual cards associated with that iOS devices; your physical credit and debit cards will remain active and usable.