To use Tap to Pay, you’ll need an iPhone XS or later. It’ll work best with Apple Pay, but it will also work with other payment methods. In order to use Tap to Pay, you must have a contactless credit or debit card from a payment network such as American Express, Discover, Mastercard, or Visa. Initially, the service will be available to “millions of retailers” in the United States.
Aside from an iPhone, no extra hardware is required for the system to function. In order to use Square’s system, you must first link a separate device to your phone.
This is how it will operate in practice: To pay using Apple Pay, customers will hold their iPhone or Apple Watch near the merchant’s iPhone and the transaction will be completed using NFC technology, rather than a payment terminal.