Rillet opens London office to spearhead Europe push

Rillet has expanded into the UK with a new office in London, marking the US finance software company's first major step into Europe.

Its UK team is already in place in central London, with plans to build a broader local operation. Demand from customers in the UK and across Europe helped drive the decision, with the region accounting for 10% of net new annual recurring revenue.

The expansion follows a USD $100 million Series C funding round completed less than three months ago at a USD $1 billion valuation. Led by ICONIQ, with participation from Sequoia and Andreessen Horowitz, the round brought Rillet's total funding to USD $200 million.

Rillet sells accounting software that places AI agents alongside finance teams within a company's accounting system. It is entering a market long dominated by larger providers including SAP, Oracle and NetSuite, as businesses reassess how finance systems handle close processes, reporting and internal workflows.

Rillet now serves nearly 1,000 customers across 75 countries, including listed companies and fast-growing businesses. International net new annual recurring revenue has more than tripled month over month, reflecting rising demand outside the US.

Its European customers include Black Forest Labs, Temporal and Primer, which Rillet cited as evidence that UK companies were adopting its software before it established a local presence.

One of those customers is Black Forest Labs, whose finance team cited AI as a factor in choosing the platform.

"When I joined Black Forest Labs, I really wanted to build a finance function that embodied our companies ambition of pushing the frontier of what was possible. We chose Rillet for our ERP because they matched that ambition. Our tech stack needs to have AI at its core and that extends beyond features like MCP connectivity. We need AI that's built into the architecture, with reliable data that we can both act on and interact with. Rillet provides all of this," said Dave Arkell, Chief Financial Officer, Black Forest Labs.

London base

London was the natural starting point for Rillet's European expansion because of the city's concentration of finance and accounting talent, professional services firms and growth companies. The company is building a larger organisation in the capital, with hiring planned across multiple functions in the coming months.

The launch also has a personal link for Nicolas Kopp, who studied accounting at the London School of Economics and previously worked in the City. He said the company had already gained traction with British customers within a year of launching in the US.

"Within a year of launching in the US, we already had finance teams in the UK running on Rillet," said Nicolas Kopp, Chief Executive Officer and Founder, Rillet. "Those teams are building some of Europe's most ambitious companies, and they deserve a finance partner that keeps up with them. Finance leaders want to know the people behind their systems are close by and committed to them, and a London team lets us be exactly that."

Partner network

Part of Rillet's European push rests on relationships with accounting and advisory firms. Its network includes an alliance with EY, a strategic alliance with RSM, and partnerships with more than half of Accounting Today's top 20 CPA firms.

Those ties matter because finance software buying decisions often involve auditors, advisers and systems integrators, particularly for larger companies changing core accounting platforms. A local team in London gives Rillet a base to deepen those relationships across the UK and the wider region.

Rillet also plans to extend its Close Club community to Europe. The group already connects more than 1,500 finance leaders in the US and is intended as a forum for Chief Financial Officers and finance teams to exchange ideas and compare experiences.

The UK launch comes as finance departments face pressure to automate routine work, shorten reporting cycles and adapt to the use of AI in business systems. For smaller software providers entering Europe, local staffing and customer support are often critical tests of whether early demand can be converted into sustained market share.

Rillet said UK and European customers were already contributing enough new revenue to justify that investment, and that its founding British team is now on the ground in London.