Apple’s new payment service — Apple Pay —debuted in the US on 20 October with a straightforward sign-up that garnered positive reviews — thanks to its existing relationship with banks and credit card issuers.

If a credit or debit card is already on file with iTunes then a cardholder with an iPhone 6 and 6 Plus can simply select the card from their iTunes account as the default for Apple Pay purchases.

Alternatively, the cardholder can use the in-app camera to capture their card information, or manually type in the card information.

The first card added to Apple Pay automatically becomes the default account, however the cardholder can tweak the setting should they wish.  “While the overall set up is similar [to Google Wallet], the Apple Pay process is slightly bit faster, mainly because of Apple’s relationships with banks and credit card issuers,” said GigaOm.

While agreeing the set-up was “easy and seamless”, BI Intelligence said retail staff were uninformed about Apple Pay, which could hinder adoption.  The firm also concluded that Apple Pay makes shopping easier because it requires fewer steps than cash or credit for in-store shopping, and does feel more secure.

It also found that trying to complete a refund with Apple Pay was difficult and that in-app purchase options were limited.

Last week, CEO Tim Cook was bullish: “We believe that Apple Pay is going to be huge, changing the way we pay for things.”.

The company has certainly laid the groundwork by building the partnerships it needs to launch such a service.

Partners include the three largest credit card firms, as well as leading banks and merchants, both online and in the physical world.

Apple announced at its September launch of Apple Pay that American Express, Bank of America, Capital One Bank, Chase, Citi and Wells Fargo were supporters. Now it said 500 more US banks have signed up.

The company also gave out a wider list of supporters from the retail sector than at launch.

However, it is unclear if the new additions have just been signed up or Apple had chosen to release more names.

Still notable by their absence are leading retailers Wal-Mart and Best Buy, backers of the rival CurrentC payment service.

Users authorise an in-store payment by holding their iPhone near the contactless reader while keeping a finger on Touch ID fingerprint authentication on their phone screens.

Cook also listed online merchants supporting Apple Pay at launch including: Apple Store app, Chairish, Fancy, Groupon, HotelTonight, Houzz, Instacart, Lyft, OpenTable, Panera Bread, Spring, Staples, Target and Uber.

Others will support Apple Pay by the end of this year with their apps such as Airbnb, Disney Store, Eventbrite, JackThreads, Levi’s Stadium by VenueNext, Sephora, Starbucks, StubHub, Ticketmaster and Tickets.com, among others. The original announcement hadn’t said which online merchants were supporting Apple Pay.

Touch ID is also used to authorise in-app payment with Apple Pay.

For shopping in stores, Apple Pay will work with iPhone 6, iPhone 6 Plus and with Apple Watch, upon availability. For online shopping within apps, Apple Pay is available on iPhone 6, iPhone 6 Plus, iPad Air 2 and iPad mini 3.