AI Accounting Unicorn Rillet Launches in UK Following $100M Series C Raise

Rillet, an agentic ERP platform, has established a London office to support its expansion into the UK and European markets. With 10% of its recurring revenue already originating from the region, the move signals a shift toward AI-native financial infrastructure for high-growth firms looking to replace legacy accounting systems with automated, data-driven solutions.

What was announced

Rillet is launching its UK operations with a central London office and a dedicated local team already on the ground. The expansion follows a significant $100 million Series C funding round closed less than three months ago, which valued the company at $1 billion. That investment round was led by ICONIQ, with participation from Sequoia and Andreessen Horowitz. The company reports that its international net new ARR has tripled month over month, now serving nearly 1,000 customers across 75 countries.

Key European clients already utilizing the platform include AI-focused firms like Black Forest Labs, Temporal, and Primer. Rillet’s platform is designed as an "agentic" ERP, meaning it utilizes AI agents to automate core accounting and finance functions rather than just providing static recording tools. This architecture is intended to help finance teams close their books more efficiently and interact with reliable data in real-time.

Alongside the technology, Rillet is introducing its "Close Club" community to Europe, a network that already connects over 1,500 finance leaders in the US. The company is also leveraging existing global alliances with major accounting firms, including EY and RSM, to build local credibility. Founder Nicolas Kopp, an LSE alumnus, is leading the push into the City to tap into London’s deep pool of accounting and professional services talent.

The companies involved

Rillet is a modern enterprise resource planning (ERP) provider that focuses on automating the "close" process and other finance operations through AI. The company has quickly ascended to "unicorn" status following its recent $100 million injection from prominent Silicon Valley investors. ICONIQ Capital, the lead investor in Rillet's Series C, is a high-profile investment firm known for managing the wealth of tech billionaires and backing major enterprise software players. Sequoia and Andreessen Horowitz (a16z) are also key backers, bringing significant weight to Rillet’s market position.

On the professional services side, Rillet operates within an ecosystem that includes EY and RSM UK. EY is one of the "Big Four" global accounting firms, while RSM UK is a leading provider of audit, tax, and consulting services to the middle market. These partnerships are critical for Rillet, as they allow the platform to be integrated into the workflows of the very firms that audit and advise its target customer base of fast-growing enterprises and publicly listed companies.

What FF News has reported before

FF News has tracked the activity of Rillet’s key partners and investors as they deepen their involvement in AI and fintech infrastructure. We recently covered how EY and INSTANDA Forge Strategic Alliance to Accelerate AI-Augmented Insurance Transformation, highlighting EY’s broader strategy of integrating AI into core financial architectures. Additionally, Rillet’s backers have remained active in high-valuation rounds, such as when Whop Secures $200M Series D at $5.1B Valuation in a round led by Sequoia. These reports underscore a trend of massive capital flows into platforms that automate complex business operations through advanced software agents.

What this means

The arrival of Rillet in London puts significant pressure on legacy ERP providers like NetSuite and Sage, which have long dominated the UK mid-market. While traditional systems have added AI "features," Rillet’s "agentic" approach suggests a fundamental architectural shift where the software performs tasks rather than just recording them. For the UK fintech sector, this expansion validates London as the primary bridgehead for US firms entering EMEA, despite post-Brexit complexities. The real test for the industry will be whether AI-native platforms can maintain data integrity at scale while satisfying the rigorous compliance and audit requirements of the UK’s financial regulatory environment.