At the end of 2018, Tandem had almost 500,000 customers, smashing the company’s earlier expectations of having around 150,000 customers by the end of the year.
“We have grown incredibly quickly. I don’t think there’s any bank in the UK that has rolled out six financial products in a year. It’s been unbelievable if you think about it,” Mr Ford said.
Tandem is one of a growing number of online challenger banks, alongside Starling, Revolut and Monzo, which sprung up in the wake of the financial crisis.
Even though those banks are increasingly drawing customers in with their apps offering more online tools to manage money, they say there is still plenty of room to grow.
In the UK, the six largest lenders hold around 87pc of current accounts, whereas in the US, the six largest banks control 54pc.
Investor interest in financial technology companies has been booming over the past year, and Monzo recently achieved “unicorn” status, as its valuation hit more than $1bn.
British peer-to-peer lender Funding Circle also became a “unicorn” when it floated on the London Stock Exchange last year.