Rillet Raises $100M at $1B Valuation to Put AI Agents Inside the General Ledger

Rillet, the startup building an AI-native ERP for modern finance teams, has raised a $100 million Series C at a $1 billion valuation. The round was led by ICONIQ with participation from Sequoia, Andreessen Horowitz, Sequoia Global Equities, Bain Capital Ventures, Oak HC/FT, Battery Ventures, FirstMark, Scale Venture Partners, and Creandum. It is the company’s third fundraising round in roughly 14 months, bringing total funding to more than $200 million.

The number that explains the valuation is not the raise itself but the growth underneath it: Rillet says new annual recurring revenue doubled in the last three months, and the platform now serves more than 600 customers — including publicly listed enterprises and, notably, several of the fastest-growing AI companies in history. Mercor, Function Health, and Temporal all run their accounting on Rillet.

From system of record to operating layer

The strategic claim at the center of the announcement is a re-architecture of what an ERP is supposed to be. For two decades, enterprise resource planning systems have functioned as systems of record — passive databases storing what already happened, while the actual work of finance happened in spreadsheets and bolt-on tools layered on top.

Rillet’s CEO and co-founder Nicolas Kopp argues that the agentic AI era breaks that model entirely. “For the last two decades, the ERP has been treated as a system of record, a place to store what already happened,” Kopp said in the announcement. “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.”

The architecture behind that claim is a vertical integration play. Structured financial data flows through native integrations directly into a real-time general ledger. AI agents then operate inside that ledger — with full context, a complete audit trail, and human approval gates where judgment is required. Instead of giving an agent read-only access to records stored in a legacy system and hoping it reasons correctly about a fraction of the data, Rillet makes the ledger itself the environment in which agents act.

This is a meaningful divergence from the prevailing pattern in enterprise AI. Most current products layer agents on top of systems that were never designed for them, repeating the spreadsheet-era pattern of workarounds around a passive core. Rillet’s bet is that agents bolted onto legacy ERP will always be second-class citizens — and that the winning architecture puts humans and agents in the same environment, sharing the same financial truth, dividing the work, and keeping every action auditable.

Accounting superintelligence, with a harness

Rillet calls the destination “accounting superintelligence” — AI agents performing increasingly complex financial work directly inside a real-time general ledger. The framing matters less than the operational design: agents get context, teams keep control. Finance professionals retain visibility, approval authority, and a complete audit trail, while agents handle a growing share of operational accounting work: reconciliation, flux analysis, accruals, and close management across a continuous-close architecture where journal entries are booked in real time rather than in a monthly sprint.

The customer evidence is the most striking part of the story. Finance teams at Mercor, one of the AI era’s fastest-growing companies, are working alongside Rillet’s agents to scale past $2 billion in ARR with a finance team of three people. ICONIQ General Partner Seth Pierrepont, who joins Rillet’s board, described multi-billion-dollar businesses operating with finance teams a tenth of their traditional size, closing their books continuously.

“In our view, Rillet is the clear market leader in AI-native accounting infrastructure,” Pierrepont said. “We believe Rillet is the foundational infrastructure for the next generation of enterprises in the AI era.”

Displacing the legacy stack

Rillet’s expansion narrative is now explicitly about replacement, not coexistence. After proving the platform with tech and AI companies, the company is pushing into biotech, healthcare, fintech, logistics, and professional services — verticals where large enterprises are pulling out Oracle Fusion, SAP, Workday, Microsoft Great Plains, and NetSuite to run accounting on Rillet instead.

The company has also been deliberate about building credibility with the accounting establishment. Rillet and Ernst & Young launched a finance transformation alliance earlier in 2026, and the company is an official partner with more than half of the Accounting Today top 20 CPA firms. For a category that lives and dies on auditor trust, that distribution channel matters as much as the technology.

Analysis: the harness thesis

The broader significance of Rillet’s raise extends past accounting software. The company has become one of the clearest expressions of a thesis now spreading across enterprise software: in the agentic era, the application layer and the agent layer collapse into one system. The “harness” — the controlled environment where humans and agents share context, policies, and audit infrastructure — becomes the product.

That thesis has consequences for the entire legacy ERP market. If finance agents work best inside the ledger rather than on top of it, every bolt-on AI layer for NetSuite or SAP is architecturally disadvantaged, and the moat shifts from data storage to the quality of the environment agents operate in. It also sets a template other verticals — legal, HR, supply chain — are already copying.

There are real questions worth flagging. A $1B valuation on a company roughly a year past its Series B prices in continued hypergrowth, and accounting is a market where incumbents are entrenched, switching costs are brutal, and AI-native upstarts (and the incumbents’ own agentic features) will compete hard for the same budgets. Doubling new ARR in a quarter is extraordinary; sustaining that across verticals with different compliance regimes is the actual test. And “superintelligence” framing for ledger automation invites the skepticism that enterprise AI marketing has earned this year.

But the direction is hard to argue with. “In 2-3 years, every company will run finance this way — agentic and in real-time,” Kopp concluded. “We’re building the system of context and harness that will take them there.”

The round suggests ICONIQ, Sequoia, and a16z agree — and that the agentic enterprise stack is now being funded not as a feature layer, but as the core system.

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