Set up by VocaLink in 2013, Zapp is aiming to bring real-time mobile payments - in store, online and through apps - to millions of Brits by integrating its system into bank apps and tapping into the Faster Payments rails.

In January five major financial institutions - HSBC, first direct, Nationwide, Santander and Metro Bank - committed to embedding Zapp within their phone and tablet apps, bringing the technology to their 18 million customers.

Sainsbury's, Asda, House of Fraser and Shop Direct are among major British retail brands announcing their support for Zapp today. Other major retailers and billers partnering with Zapp include: Thomas Cook, Clarks, Dune, Spar, Best Western, Starstock, QD Stores, Anglian Water, Bristol & Wessex Water, Sutton and East Surrey Water. Support for Zapp from the charity sector through Oxfam and Charities Aid Foundation has been previously announced.

Initially scheduled for launch later this year, the timeframe has now been extended for a commercial rollout in "the front half of 2015". VocaLink says the core Zapp technology has been successfully built and delivered and pilots are being planned before the brand is introduced to the general public. Zapp says it intends to invest "tens of millions of pounds" in advertising and promotional activity, including a consumer education campaign, above the line advertising and promotional activity at the point of sale.

Peter Keenan, chief executive of Zapp, comments: "At last the promise of a truly mobile and digital payment method will become a reality, meaning easier and more secure checkouts for millions. It's amazing to have the support of such well known retailers. Together with our other partners this means millions of consumers will be able to shop at tens of thousands of merchants up and down the UK at launch."