Can more than one person’s face be stored on the iPhone X?
The biometric information for only one face can be stored on the device for Face ID. You should ensure that only your biometric information (facial data) is stored on your device. Each time the device registers a use of biometric information to authorise any transactions through Mobile Banking, you instruct us to perform those transactions.
This means that you should not register for Face ID sign in if you would like to have another person's face stored on your device.