Google is launching Android Pay, its tap-and-go contactless payment service, in the UK.
Nearly 60% of the country's smartphone users own an Android handset.
Devices running Android 4.4 or higher and fitted with an NFC (near field communication) chip will be able to use the service.
The firm said it had chosen the UK as the next place to offer mobile payments because of British familiarity with contactless payments.
Until now, the facility had only been available in the US.
Apple Pay has been in use in the UK since last summer, with thousands of retail outlets - from sandwich shops to the London Underground - now accustomed to customers using their phones to pay.
I've had a preview of the Android Pay app, and if anything it is even simpler to use once you have uploaded your cards to the app.
Your phone has to have some kind of lock - a fingerprint, or pattern or Pin code - but when the device is on, you don't even need the app to be open to tap-and-pay on a contactless terminal.
For now, just as with Apple Pay, most retailers will only allow payments up to £30 using your phone. The promise is that a software upgrade to payment terminals will allow higher amounts, although you will then need to use your unlock method to authorise the transaction.
Given that Apple last year listed a number of retailers that would be accepting higher payments, and only a handful have so far done that, I would be surprised if there is rapid progress on this front.
At launch, many Visa and Mastercard credit and debit cards will work with the app, although Barclays customers will not be able to use Android Pay. That is because the bank is going it alone, making contactless payments available through its own mobile banking app.
To add to the confusion - or perhaps choice - the leading maker of Android phones is launching its own payments service. Samsung Pay arrives in the UK "later this year" and, according to a spokesman, will offer a uniquely simple solution combined with special offers for users.
Here's where the closed nature of Apple's operating system, compared to Android, may prove an advantage - for Tim Cook's business at least.
I'm sure that Barclays would prefer that its iPhone-wielding customers could use its mobile banking app to make contactless payments, but because Apple does not allow outsiders to come anywhere near the NFC functionality on its phone that is not possible.
So, is this the moment when the dream of your phone becoming a mobile wallet - promised for at least a decade - becomes a reality?
That was supposed to happen with Apple Pay but a source in the payments industry tells me that was a bit premature. "Last time I looked at our figures, one in 10 payments was contactless, but fewer than one in a 100 were from a mobile phone," he said.
But he went on to point out that contactless cards, first launched in the UK in 2008, had also been slow to take off. The decision of Transport for London, Europe's biggest single retailer, to allow the use of contactless credit and debit cards on buses and tube trains, had been the tipping point.
Nowadays, shop staff in the capital seem embarrassed when they tell you that they cannot take contactless payments.
Android Pay, with a huge potential audience in the UK, could do for the mobile wallet what TfL did for contactless cards. For the first time, just about anyone who owns a smartphone can use it to pay.
If they discover it is simple, convenient and that they can get access to money saving deals via their phones, then paying by card could begin to look as old-fashioned as writing a cheque.