Rillet raises USD $100 million at USD $1 billion valuation

Rillet has raised USD $100 million in a Series C round at a USD $1 billion valuation. ICONIQ led the financing, with participation from existing investors including Sequoia and Andreessen Horowitz.

The accounting software company has now raised more than USD $200 million in total, marking its third capital raise within a year. Other investors in the round included Sequoia Global Equities, Bain Capital Ventures, Oak HC/FT, Battery Ventures, FirstMark, Scale Venture Partners, and Creandum.

Rillet plans to use the funding to expand software that combines a real-time general ledger with artificial intelligence tools for finance teams. It describes the product as an operating layer for finance departments, where staff and software agents work from the same financial data and controls.

The San Francisco-based company said growth had accelerated ahead of the raise, with new annual recurring revenue doubling over the past three months and its customer base growing to more than 600.

According to Rillet, those customers include public companies as well as fast-growing artificial intelligence businesses. The company said it first gained traction with technology and AI groups before expanding into sectors including biotech, healthcare, fintech, logistics, and professional services.

Some clients are replacing older finance systems from Oracle Fusion, SAP, Workday, Microsoft Great Plains, and NetSuite. Rillet argues that many existing enterprise resource planning systems still function mainly as repositories for completed transactions, leaving substantial work to spreadsheets and add-on software.

Finance focus

Its software is designed to move data through native integrations into a real-time ledger, while AI agents operate within that ledger rather than on top of separate systems. Rillet said finance teams retain approval authority and a full audit trail as those agents take on more work.

Nicolas Kopp, Chief Executive Officer and Co-Founder of Rillet, outlined the company's view of how finance software is changing.

"For the last two decades, the ERP has been treated as a system of record, a place to store what already happened. In the AI era, it has to become the operating layer for what happens next. Finance agents need more than access to data; they need to work inside the general ledger," said Nicolas Kopp, Chief Executive Officer and Co-Founder of Rillet.

"Rillet is building that harness: one environment where humans and agents share the same financial truth, divide the work, and keep every action auditable. The result is a finance function that can operate 24/7 and in real time," Kopp said.

Rillet said its customer base shows how that model can reshape finance team structures. It cited Mercor as an example of a business using Rillet's AI agents while operating at more than USD $2 billion in annual recurring revenue with a finance team of three.

Investor backing

For ICONIQ, the round reflects a bet that accounting and finance systems are becoming a more important application area for AI. The investor also took a board seat as part of the deal.

"In our view, Rillet is the clear market leader in AI-native accounting infrastructure," said Seth Pierrepont, General Partner at ICONIQ.

"What stands out to us is how customers actually run on it - multi-billion-dollar businesses operating with finance teams a tenth the traditional size, closing their books continuously. We believe Rillet is the foundational infrastructure for the next generation of enterprises in the AI era, and we are proud to deepen our partnership," Pierrepont said.

Rillet has also sought to deepen ties with accounting firms that advise large companies and oversee audits. It said it launched a finance transformation alliance with Ernst & Young earlier this year and is now an official partner of more than half of the Accounting Today top 20 CPA firms.

The latest fundraising comes as investors continue to back software groups applying AI to back-office functions, an area seen as more likely to deliver measurable gains than some consumer uses of the technology. Finance departments have become a particular target because they manage structured data, rules-based processes, and compliance requirements that lend themselves to automation while still demanding human oversight.

Rillet's pitch is that this work should sit inside the accounting system itself rather than in separate software loosely connected to older ledgers. That puts it in competition not only with established enterprise software providers, but also with newer AI vendors trying to layer automation onto legacy finance systems.

"In 2-3 years, every company will run finance this way - agentic and in real-time," said Kopp.

"We're building the system of context and harness that will take them there and redefine what's possible for the finance team of the future," Kopp said.