Closing a company’s books still means chasing transactions, reconciling accounts and checking that the numbers agree. Rillet wants AI agents to handle more of that work inside the system where those numbers live.

The New York-based company announced a central London office on November 9, taking its challenge to established accounting platforms—including SAP, Oracle Fusion and NetSuite—further into Europe.

Its UK team is already in place, with more hiring planned. According to Rillet, European customers already generate 10% of its net new annual recurring revenue, giving the expansion a customer base to build on.

$100 Million to Challenge the Accounting Incumbents

Rillet raised a $100 million Series C at a $1 billion valuation on August 17, led by ICONIQ with participation from Sequoia and Andreessen Horowitz. The round brought its total funding to more than $200 million.

At the time, Rillet reported more than 600 customers. Its November announcement puts that figure at nearly 1,000 across 75 countries, including publicly listed businesses. Rillet’s funding announcement.

The company also says international net new ARR more than tripled month over month. That measures the pace of new recurring business; it does not mean Rillet’s entire international revenue base tripled. The announcement does not disclose an absolute ARR figure.

The funding is backing a specific product bet: finance teams will increasingly choose accounting systems designed for people and AI agents to work together.

What Does an AI Accounting System Actually Do?

Rillet calls its product an “agentic ERP.” ERP stands for enterprise resource planning, a category of business software that includes the systems companies use to manage their finances.

At the centre of Rillet’s platform is the general ledger—the main record of a company’s financial transactions. Its approach puts AI agents directly alongside that record, with access to the context, accounting policies and controls needed to perform work.

The platform combines transaction processing, account reconciliation, reporting and tools for spotting unusual activity. Rillet says finance teams retain approval authority and an audit trail showing what happened.

For a growing business, the appeal is practical: spend less time moving information between spreadsheets and applications, and make it easier to review the work that produces the final accounts.

Rillet is also pushing toward what it calls a “Zero-Day Close,” where accounting work happens continuously. In an October 27 post, the company said customers were closing their books twice as fast on average and set a goal of bringing every customer to a zero-day close within 12 months. That is a company-reported result and a future target, rather than a guarantee for every finance team.

Why Black Forest Labs Chose It

Rillet names Black Forest Labs, Temporal and Primer among customers supporting its European expansion.

For Black Forest Labs CFO Dave Arkell, the choice reflected a desire to build a finance function that matched the company’s wider ambitions. He said AI needed to be part of the underlying system, supported by dependable information.

“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.”

— Dave Arkell, CFO, Black Forest Labs

A London team adds local support to that proposition. Rillet also plans to bring its Close Club community to Europe, extending a network that it says already connects more than 1,500 finance leaders in the US.

Its relationships with EY, RSM and other accounting firms provide another route into businesses considering a change of systems.

AI Is Moving Deeper Into the Finance Department

The expansion fits a broader shift Blockster has been following.

Ripple’s AI treasury tools focus on cash management and financial decisions. Space and Time Enterprise lets businesses verify calculations without exposing the underlying private records. Rillet is targeting the accounting workflow itself: the system where transactions become financial statements.

For Rillet, the next test is turning its early European demand into sustained adoption. Replacing an accounting platform requires confidence in the data, the controls and the people supporting it. Its London expansion puts a local team behind that promise.

Reporting by Sasha Steenkamp

AI