The digital bank Starling is to create 400 new jobs in the centre of Cardiff.
It said it was going to recruit all 400 posts in data science, fraud and customer service this year, with plans to employ more in future.
Anne Boden, a steelworker’s daughter from Swansea, set up the new style bank in 2014 after having a successful career in high street banking.
Starling has since grown to employ 800 people in London and Southampton, offering personal and business banking.
The bank, which has 1.3 millions accounts, is taking office space at Brunel House in the centre of Cardiff.
Ms Boden said: “The Welsh tech sector is one of the fastest digital economies outside of London, and continues to grow. Cardiff is also a bright, dynamic and entrepreneurial city with a supportive ecosystem which we are looking to tap into as we continue to grow our business and personal accounts.
“We believe that London’s success as a fintech hub should enable it to spread wealth and jobs throughout the UK and the wider economy. That’s exactly what we’re doing with this office in Cardiff.”
The bank said it was not receiving any financial support from the Welsh Government for the investment.