How do I use my Apple Watch for Apple Pay using ONLY my passcode?

Harry,

Apple Watch requires a passcode whenever you 1) choose to use one for security of data on your Apple Watch and 2) if you are loading credit or debit cards on your Apple Watch. The credit cards are loaded via the Apple Watch App on your connected iPhone. To use Apple Pay, you first must ensure that the pass code has been entered - no blue lock at the top of the watch face. Next you double tap the side button to call up the Apple Pay app and swipe right to select the card you want to use if it is not the default card. Then hold the watch face to the pay terminal sensor. You will get a beep and a buzz when the payment is completed. You do not even need to have your iPhone with you to use Apple Pay. Apple Pay is only available on the new iPhone 6 and 6 Plus, but you can use an iPhone 5, 5C or 5S to set up Apple Pay credit cards on your Apple Watch.