Update expiration date and CVV on Apple Pay

Please follow this path;

iPhone > Settings > Apple ID (Your Name at top of screen) > Payment & Shipping > tap Edit (upper right corner of screen) > tap edit (upper right corner of screen) > tap expires (enter as MM/YYYY) > enter 3 digit 3 digit CVV security code > update phone number etc > tap Save

The expiration date needs to be updated to a 4 digit number for the year and in the following format, MM/YYYY.

Just click on the expiration date text field and enter the correct date. You may also need to re-enter the 3 digit CVV security number and also the phone number.