This is the big one: using your iPhone to pay for your purchases. It’s a snap to set up. Launch Passbook, and if you already have a card linked to your Apple ID -- which is how you buy apps and media from the App Store and iTunes -- your card should be listed there if it’s one of Apple Pay’s partner cards. If you don’t have a linked card, or you want to add a different one, you’ll see the option to add a card to Apple Pay. Your iPhone’s camera will launch, and then you’ll simply take a picture of the card. It may take a few seconds for the issuing bank to verify the information. But once that happens, you’re ready to begin using Apple Pay -- assuming you’re in the United States. (You can add multiple credit and debit cards to Apple Pay, and you can also change the default card for payments by going to Settings > Passbook & Apple Pay.)
Several retailers, apps, banks, and card providers are already on board. To use it in a brick-and-mortar store, place your iPhone on the cash register’s payment terminal. Your iPhone will detect the terminal and launch Passbook, and then Touch ID will request your fingerprint to complete the purchase.
Yes, it’s that simple, and yes, it’s secure. Thanks to Apple’s “secure element” chip, which encrypts your payment information, neither the retailer nor Apple has access to your actual credit card number. Retailers don’t even see your name.
Hardware requirements limit Apple Pay to the iPhone 6, iPhone 6 Plus, iPad Air 2, iPad Mini 3, and the upcoming Apple Watch. Because the new iPads do not include an NFC chip, they can only use Apple Pay for in-app purchases and not at retail point-of-sale terminals.