Powa Technologies, a British e-commerce tech firm, has formed a "strategic alliance" with China's biggest payments processor, China UnionPay.
The joint venture could generate $5 billion U.S. in revenues over three years, said Dan Wagner, Powa's chairman and chief executive.
China UnionPay has about 4.5 billion credit and debit card users worldwide.
Powa's technology enables shoppers to pay for goods quickly in-store and online using their smartphones.
The joint venture, PowaTag UnionPay, will launch first in Guangdong Province, targeting 400,000 retailers, the company says, before rolling out to one million by the end of 2016.
China's six million merchants will pay about 13 pence per transaction to the joint venture for access to the technology
The PowaTag system relies on digital tags - quick response codes - that can be attached to physical goods or inserted into self-service checkout screens, emails, websites, posters, images - even the audio from TV ads.
The company says wherever Chinese shoppers see the PowaTag UnionPay symbol, they will be able to buy products by scanning them with their phones and tapping the "buy now" button.
