The two Estonians taking on the banks
6 October 2015 Last updated at 00:01 BST
"Whenever you move money around the world, banks take a cut, it's a big cut and it's unfair," says Kristo Käärmann, co-founder of TransferWise.
Together with fellow Estonian Taavet Hinrikus, he set up TransferWise, which aims to shake-up the banks' dominance of global money transfers and make it cheaper for people to move money overseas.
Four years on the business transfers £500m ($760m) monthly.
The firm's co-founders explain how they got started.