VocaLink is currently working to get banks and retailers on board by the end of the year so it can launch Zapp to consumers in early 2014, when it will target all commerce channels, mobile, online and in-store.

Banks who agree to take part in the service will integrate Zapp into their mobile apps and then invite customers to opt in, linking their bank account to their phone number.

Then, at participating retailers, users shopping on their phone or tablet who click the pay by Zapp button will be taken to their mobile banking app, where they will be shown their account balance before being asked to confirm the transaction.

On a desktop or in-store, the payment terminal or browser will generate a six digit Zapp code which the user enters into their mobile app to complete the transaction.

By sidestepping cards, VocaLink argues that Zapp will help Brits unlock the money in their current account in a much simpler and more secure way because no information is passed to the recipient. Meanwhile, retailers will benefit from instant payments and fewer abandoned shopping carts.

Zapp CEO Peter Keenan stresses that the service is completely separate from the Payments Council phone number-based mobile payments offering - to launch next year - for which VocaLink is building the central database. That service will focus on person-to-person payments, while Zapp is purely about consumer-to-business transactions.

Although, VocaLink has refused to provide names, it is understood to have secured the commitment of several banks and retailers to the service, in which it has already invested £16 million.

Zapp is now inviting retailers and other potential partners such as telcos to buy stakes in the venture in a bid to raise around £100 million.

David Yates, CEO, VocaLink, says: "We are proud to be collaborating with financial institutions and retailers to spearhead the creation of a new payment system, which gives all of us easy access to the money in our bank accounts by using cutting-edge, secure technology through the mobile phone."

Last week Finextra revealed that Barclays is planning to extend its mobile phone number-based P2P payments service, Pingit, to retailers. Launching soon, the Buyit feature will let users make purchases by scanning QR codes on adverts.

Fiona Ghosh, payments expert at global law firm Eversheds, thinks that the emergence of Zapp, Buyit and others could spell trouble for card firms.

"Instant mobile payment initiatives like Buyit and Zapp involve direct bank transfers, which are cheaper for retailers than credit card payments, which come with interchange fees and other bank card transaction fees attached. This is bad news for credit card companies, who are already awaiting the European Commission's ongoing investigations into Visa and MasterCard's multilateral interchange fees," says Ghosh.