When Apple first unveiled its mobile payment system called Apple Pay last year, the company said it would work with the iPhone and the forthcoming Apple Watch. Today, Apple unveiled more information about the Apple Watch, including more details on the Apple Pay functionality.
Here’s how Apple Pay is supposed to work on the Apple Watch:
First, you need to own an iPhone — a 6, 6 Plus or a 5, 5c or 5s — to use Apple Pay with the Apple Watch. Watch owners have to open the Apple Watch app on their iPhone, which Apple is installing on phones as part of an iOS software update. Once the Apple Watch app is open, you tap the Passbook and Apple Pay option in the app to add a credit or debit card to be used for in-store payments using the Apple Watch.
This process links payment information with the Apple Watch, though the watch doesn’t store your actual card or account information. Instead, the watch stores a unique placeholder code. This code only gets matched up with your actual credit card account after a store where you’re shopping sends the placeholder code to the bank or credit card company that issued you the account.
You also need to create a passcode when setting up Apple Pay for the Apple Watch. This will come in handy to keep someone from using your watch for a shopping spree if they steal it. That’s because each time you put the Apple Watch back on after taking it off, you will need to enter your Apple Pay passcode to unlock the payments functionality on the watch.
Now you’re ready to blow a cashier’s mind and pay with your watch. When you are ready to pay at a store that accepts Apple Pay, you tap the button on the side of the Apple Watch twice, and then place the watch’s face against the payment terminal. The payment information is transmitted.
One more thing worth pointing out: While you need to own an iPhone to use Apple Pay on the Apple Watch, you don’t need to have the phone with you to pay in a store using your watch. The Apple Watch stores both the payment information and NFC chip necessary to make a purchase happen all on its own.
This article originally appeared on Recode.net.