LONDON — Fintech is a big business in the UK.

The British Treasury has now held two conferences to promote the country's burgeoning financial technology industry on the world stage and the government estimates that the entire sector is worth £7 billion to the UK economy. That's up from almost nothing a decade ago.

Business Insider has covered UK fintech since our 2014 launch. The UK Fintech 35 under 35 highlights the most promising young entrepreneurs, engineers, marketers, and sector experts under the age of 35. It spans both startups and big banks operating in the sector.

Here's who made the cut: