Note: The Apple Watch will work with any iPhone 5 or newer, but only the iPhone 6, 6 Plus, Apple Watch (and the latest iPad) can use Apple Pay. You can still set up Apple Pay for the Apple Watch with an iPhone 5 (or 5S, or 5C), because the necessary Secure Enclave is in the Watch, not on the older phone.
Once Apple Pay is set up on the Watch, there's no separate app needed to use it — and the iPhone doesn't even have to be with you. After it's pre-configured, the Watch can be used anywhere Apple Pay is supported. To make a payment, simply press the side button beneath the Digital Crown twice, and hold your wrist up to a payment terminal. The Watch will vibrate and play a confirmation sound when the transaction is complete. (To choose between credit cards, you use the swipe gesture after pressing the Watch button twice.)
As with the iPhone, iCloud.com can be used to remove the cards you've associated with a lost or stolen Watch. But since the Watch's sensors detect when it's off your wrist — and require that four-digit passcode to authorize future purchases — you're most likely safe.
Just a four-digit code?
My only complaint? I'd like to see a longer passcode. I have a 10-digit passphrase on my phone, and online passcodes that are two-dozen digits long. So the four-digit passcode seems like the bare minimum you'd want for basic protection. It'll be enough to generally protect users, but why limit the passcode to four digits? Why not six, or eight? I'd trust a 6-digit password over a 4-digit one, and an 8-digit code over a 6-digit one, for sure. It's not like it would take longer to tap in and would add a little more security to the device. But I'm obviously picking nits.
With its usual attention to detail, ease of use and user experience, Apple has made it easy to buy things using devices you carry with you anyway. It won't be long before the whole idea of taking out your wallet, fumbling for the right card, swiping it at a store and punching in a PIN code will be a distant memory. That day gets much closer as soon as the Apple Watch arrives.
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