Daniel Klein co-founded Moneybookers, the digital wallet later renamed Skrill, before turning to small business payments.
SumUp was founded in 2012 and shipped its first product in August. Klein is a co-founder, alongside Marc-Alexander Christ, Jan Deepen, Stefan Jeschonnek and Petter Made.
For its first four years SumUp fought Payleven, a rival backed by Rocket Internet. The two merged in 2016, and Klein became CEO of the combined company.
By 2022 SumUp had about 3,000 staff and over 3.5m merchants in more than 30 markets, with a valuation of about €8bn. In May 2024 it raised €1.5bn in a round led by Goldman Sachs.