Rillet's AI-Native Accounting Platform Hits $1B Valuation, Challenges Legacy ERP

Rillet, a two-year-old startup building an AI-native accounting platform, has raised a $100 million Series C at a $1 billion valuation. The round was led by ICONIQ with participation from Sequoia Capital, Andreessen Horowitz, Oak HC/FT, and new investors including Bain Capital Ventures and Battery Ventures, pushing total funding past $200 million. Fortune

For AI builders and product teams, Rillet is a useful case study in agent-first back-office automation. The platform is built around AI agents that run hundreds of operations in parallel, handling manual accounting work that traditionally consumed finance teams. CEO Nicolas Kopp positions it as a helper that frees CFOs from spreadsheet drudgery, not a replacement for finance professionals. Fortune

Customer traction and the EY alliance

Rillet reports over 600 customers, including Neuralink, Skild AI, and Mercor. According to the company, Mercor's finance team uses Rillet's AI agents to manage a business scaling past $2 billion in annual recurring revenue with just three people. Fortune Roughly 40% of customers are outside tech and AI, spanning industries like waste recycling and movie studios.

Earlier this year, Rillet launched an alliance with EY for AI-native finance transformation, and it says it now partners with more than half of the Accounting Today top 20 CPA firms. Fortune

How Rillet compares to legacy ERP

Rillet's pitch is direct: legacy ERP systems like Oracle Fusion, SAP, Workday, and NetSuite were built for a pre-AI era. Kopp argues those systems were designed for humans to input and review data, leaving finance chiefs stuck in day-to-day minutiae. Rillet's agent-first architecture, by contrast, automates much of that work and produces a complete audit trail. Fortune The company claims this architectural difference lets customers close their books continuously with finance teams a tenth the traditional size.

Architectural distinction and product velocity

The core technical claim is that Rillet combines deterministic accounting data with AI agents that complete complex, end-to-end work. Kopp says proving out the work layer is mission-critical for enterprise readiness. Fortune

Product development has accelerated alongside AI model improvements. Kopp described instances where the customer support team (many with accounting backgrounds) shipped feature requests within two to three hours of a customer raising them, as engineers build tools in direct collaboration with in-house accountants. Fortune

Talent and market implications

Kopp frames the AI shift as a response to a shrinking pipeline of accounting graduates. AI agents can help make up for that talent gap while business complexity increases. He noted that tasks that once took a human a full day now take a couple of minutes, freeing time for higher-level strategic work. Fortune

Caveats

These claims come from the company and its press coverage. ARR growth, customer numbers, and the Mercor reference are vendor-reported and not independently verified. Rillet's argument that legacy ERP is being disrupted is its own market positioning. Builders evaluating the platform should validate audit trail completeness, integration depth with existing systems, and whether the agent-first approach works at their scale.