UK became the first country outside the United States to get iPhone-maker Apple's new mobile payment system Apple Pay, as it went live here on Tuesday.

After assigning credit or debit cards to their iPhones and Apple Watches, users can simply tap their devises against contactless card readers to pay for things. Apple Pay uses the iPhones' fingerprint sensor to confirm the user's identity.

Apple Pay can now be used in some major outlets in the UK, including Boots, Lidl, M&S, Starbucks, McDonalds and even London Underground. The number is expected to grow very soon, as UK's 410,000 contactless pay terminals can easily adapt to the new service.

As a payment system, it is paramount that Apple Pay has the support of credit card providers and banks. So far, major credit card providers, such as Visa, Mastercard and American Express, and several local banks, including Nationwide, NatWest, Santander, and the Royal Bank of Scotland, were on the launch list of Apple Pay.

However, some big names in Britain's banking sector are missing on the list. HSBC said it is not ready for the service, although it was previously listed as a launch partner of Apple Pay. Halifax, Lloyds and Barclays said they will join in the future as well.