Apple Pay

Apple Pay is a mobile payment device and digital wallet by Apple Inc that lets users pay through iPhone, iPad or iPod touch. The service is compatible with the iPhone 6, 6 Plus, iPhone 6S, 6S Plus, 7, 7 Plus, 8, 8 Plus, iPhone i10, iPhone SE, iPad Air 2, iPad Pro and the Apple Watch. Users with iPhone 5, 5C, 5S, 6, 6 Plus, 6S, 6S Plus, 7, 7 Plus, 8, 8 Plus, iPhone X and iPhone SE can use the service through an Apple Watch, though it lacks Touch ID security. Instead, Apple Pay is activated with a passcode and will remain active for as long as the user wears the Apple Watch.

Apple Pay implements the Contactless EMV standards from the major payment card networks and should work at any merchant that supports contactless payments worldwide, regardless if they specifically advertise Apple Pay acceptance or if Apple Pay support is offered by card issuers in that country. However, due to provisioning differences between countries (and even between issuers), users may encounter acceptance issues when travelling to a different country. Some current known issues include: Apple Pay launched in Singapore on April 19, 2016 on American Express issued cards. Since May 23, 2016, this service was extended to support Visa and MasterCard credit and debit cards issued by Singapore's five major banks, translating to about 83 percent of credit and debit cards in the country.
 * US-issued VISA cards do not support Offline Data Authentication, which prevents them from being used on certain public transport services, most notably Transport for Singapore.
 * Canada, UK, and possibly other non-US-issued VISA cards only support EMV-mode transactions and not legacy magnetic stripe data emulation transactions. Most contactless terminals in the US do not currently support EMV-mode contactless transactions (even if they support EMV contact transactions), and therefore these visitors to the US will receive a 'Could Not Complete Payment' error on the iPhone screen and an error on the terminal when attempting to use Apple Pay.
 * US-issued American Express cards do not support EMV-mode, which prevents them from being used on certain public transport services, most notably Transport for Singapore, and at terminals that do not support American Express magnetic stripe data emulation transactions.