For ten months, the office was a gym lobby.
Oliver and Alexander Kent-Braham, twins from south-west London, had a GBP 80 Virgin Active membership and a laptop each. That was the headquarters of what would become a unicorn. Oliver had quit a banking job at Investec after about six months. He describes the pair as having 'boring business type' backgrounds. Nobody was going to hand them credit for a story.
They liked the idea of something soft and friendly, and wanted a name that stood out from insurers whose names began with 'A'.
The itch came from a friend. A Canadian who had just arrived in Britain kept getting outrageous car-insurance quotes, not because he was a bad driver but because he had no UK history. The brothers realised that deeper data might show the opposite of what a thin file suggested.
So they built for the people the market overlooked. With software engineer David Goate, they incorporated the business in 2016 as Twin Thinking and renamed it Marshmallow in 2017. They liked the idea of something soft and friendly, and wanted a name that stood out from insurers whose names began with 'A'. The choice provoked a legal fight: Marsh McLennan challenged the name in 2018. Marshmallow won.
The money was small at first. In 2018 Investec, Oliver's former employer, and Passion Capital put in a $1.2M seed to build an insurer aimed mainly at migrants.
Then came the jump. In 2021 an $85M round valued the company at $1.25bn, making it a unicorn. The twins split the job: Oliver takes the outside world and fundraising, Alexander culture and product. Along the way came another legal tussle, with Mulsanne Insurance over intellectual property in 2021, settled out of court.
The growth was real. The Financial Times ranked Marshmallow the second-fastest-growing company in Europe in 2023, at a 660% compound annual growth rate, and a fresh raise of about $90M followed in 2025 at around $2bn.
What the story teaches is easy to miss. The insight was not born in the gym. It came from a friend's complaint, taken seriously, and then acted on for ten months with a very small budget.