Developed in partnership with 11:FS and Capco, Mettle will allow customers to open a business current account in minutes, forecast their business performance, create invoices from their mobile phone and provide reminders for chasing payments. All of these features will be wrapped in a single mobile app with a debit card.

Mettle is currently at pilot stage, and customers who open an account will work closely with the Mettle team to influence how the product will develop, says Alison Rose, chief executive of commercial and private banking at NatWest.

“The premise for Mettle lets our customers focus on ‘forward-looking’ finances, combining technology and proactive insights so SMEs can make better decisions and run their businesses more successfully," she says. “Being able to engage with our customers and to get their direct feedback, at this early stage, is extremely important to us. We wanted to launch this new innovative account so that customers can focus on achieving their entrepreneurial goals while staying on top of their financial commitments. With their invaluable insight, we hope to save our customers from worrying about daily account management and cash uncertainties of the future”.

The new digital banking offshoot is run independently from the bank with both customers and non customers able to apply for an account.

RBS-owned NatWest is also understood to be trialing a separate digital retail bank that would serve everyday customers, with the aim of taking on app-only challengers and moving over a million customers to the new standalone bank.

Sketchy details about the project - which will ape the approach of challenger banks with the development of a marketplace model - first emerged in March. Led by the Bank's former chief operating officer Mark Bailie, the new bank is being built by a lean team of just 80 developers and bankers at a separate London location to RBS' HQ in Bishopsgate.