Rillet raises $100M at a $1B valuation in a 48-hour Series C

AI accounting startup Rillet has raised a $100 million Series C at a $1 billion valuation. Iconiq led the round, with Andreessen Horowitz and Sequoia returning. Co-founder and CEO Nicolas Kopp said the deal came together in less than 48 hours, and the company wasn’t even looking to raise.

The trigger was a board meeting a few weeks ago, where Rillet showed investors its growth since last summer’s $70 million Series B, Kopp told TechCrunch. Annualized revenue had doubled in the last quarter alone. New clients included public companies, and an alliance with EY had landed. Two days after the texts and calls started, Rillet was a unicorn.

The track record behind that speed is short but steep. Rillet emerged from stealth in 2024 and has now raised more than $200 million, with Sequoia leading its $25 million Series A and Iconiq and Andreessen Horowitz leading the Series B. The company counts more than 600 customers and says it doubled new ARR in the last three months. Numbers like those are what a round announcement headlines, which is exactly why it pays to know what a round announcement leaves out.

Rillet had already proven it could win against the incumbents that have owned this category for decades.

Seth Pierrepont, General Partner, Iconiq, via TechCrunch

Pierrepont, whose firm co-led the Series B, joins Rillet’s board with this round. He said the deal moved fast but “wasn’t a cold start.” Julien Bek, Sequoia’s lead investor on the deal, called re-investing a “very easy decision.” Bek said agentic finance could become “one of the largest application software opportunities of the AI era.”

The customers back that up, because they aren’t running pilots, Kopp says. They’re pulling ERP and accounting software out of incumbent systems, and he broke down for TechCrunch where they defect from.

Previous provider	Share of Rillet customers
Intuit	50%
NetSuite and Sage Intacct	30%
Oracle, SAP, Workday and Microsoft products	20%

The product itself was built for AI agents rather than humans, with people working alongside the agents on corporate bookkeeping. Customers can route requests to the foundational model of their choice, such as OpenAI or Anthropic, and there’s no cross-training, so one customer’s data stays proprietary. About three months ago, Rillet shipped a governance feature that lets accountants audit every decision an agent makes, including which numbers it pulled and how it calculated them.

That audit angle explains the EY tie-up. Ernst & Young LLP announced the alliance in April, pairing EY’s finance transformation and risk and controls work with Rillet’s AI-native platform.

The backdrop is a thin talent pipeline. Kopp points to a U.S. shortage of accountants, and the Bureau of Labor Statistics projects employment of accountants and auditors growing 5% from 2024 to 2034, an increase of 72,800 jobs. The BLS reads automation as an efficiency gain rather than a job cut: “Automating some routine tasks makes these workers more efficient by allowing them to focus on analysis and other high-level responsibilities.”

Kopp agrees, and he insists Rillet isn’t a replacement even for junior accountants. “I just don’t see people losing their job anytime soon,” he said.

The thing to watch now is the rulebook. Regulations for public companies currently require a human to approve every transaction an AI agent makes, and Kopp said he’s hopeful new rules evolve toward where the technology is headed. “It’s a very normal process,” he said. “Similar to when the cloud came, of just getting everybody familiar with what’s going on and how it helps the profession.”