Zapp, the new mobile payment service due to launch in autumn, has signed with five UK high street banks so that customers will be able to use the company's smartphone and tablet application to pay for goods.

First Direct, HSBC, Nationwide, Santander and Metro Bank are the first to announce their support to the service.

Zapp works by linking users' bank accounts to their Zapp digital wallet. Not only will this offer a way to pay instantly and securely without having to use cash, debit or credit cards - including online without having to enter sensitive information - but it will also be the first service to give users information on their bank accounts in the app itself, such as the current balance. That way they can decide if they can afford an item before they buy it.

"We will be the only payment method where, at the point of sale, the customer can see the real-time balance of their accounts," Zapp chief executive Peter Keenan told the BBC.

"This allows them to say, 'I've got this much money in my account, shall I go ahead and buy this product or not?'

"And because they are using a smartphone, it allows them to keep a record of all their spending and purchases in one device."

READ: Zapp payment service lets you buy things using your mobile phone number

The app will work in shops through NFC or online through tablets and PCs. When checking out with the latter, if you are on a tablet device, the process will launch the Zapp app. If using a PC, the checkout process can send a notification to the customer's phone which will then launch the payment application.

Rival services, such as PayPal, seem undeterred by today's announcement. Welcoming, even.

"At PayPal we believe in the power of mobile - after all, we’ve helped make mobile payments happen both on and offline for some time here in the UK and we expect to have handled $20 billion in mobile payment volume in 2013 alone," commented Rob Skinner, the company's UK director of PR.

"Money’s digital switchover is under way. By 2016, we predict that you won't need a physical wallet to shop on the British high street - our vision is that the digital wallet doesn't just replace a physical wallet but is something that will include offers and loyalty schemes as well as bank accounts, credit and debit cards. That's why we welcome new players such as Zapp to the market, to join us on the road to realising the future of money."