AI Accounting Startup Rillet Raised $100M and Hit Unicorn Status in 48 Hours Without Even Trying

Rillet co-founder and CEO Nicolas Kopp seems justifiably confident as he talks over Zoom a day after his company announced a $100 million raise at a $1 billion valuation. The US has a shortage of accountants right now, which is driving growth of his AI-native accounting platform so much, Kopp says, that he raised the cash in 48 hours without even trying.

From Stealth to $1B in Two Years

Rillet emerged from stealth two years ago. Since then, it has raised $200 million from top investors including Iconiq, Andreessen Horowitz and Sequoia. It has also amassed 600 customers, most of whom are looking to ditch legacy accounting systems like Oracle and NetSuite, Kopp says. A few weeks ago, Rillet held a board meeting and shared with investors its growth since its $70 million Series B last summer. Annualized revenue rate had doubled in the last quarter alone; the startup added new clients, many of them public companies, and an alliance with EY to introduce AI tools to the auditing giant.

Why 48 Hours Was Enough

After that board meeting, text messages were fired, calls were made, and 48 hours later, Rillet was a unicorn. The company wasn't even looking to raise, Kopp said. Seth Pierrepont, the general partner at Iconiq who led the round, said the deal came together fast but "it wasn't a cold start." Iconiq also co-led the company's Series B, and with this latest round, Pierrepont joins the Rillet board. "A year of watching the team deliver on that made doubling down and leading the Series C an easy call." Julien Bek, Sequoia's lead investor on the deal, also said that though 48 hours might look rushed from the outside, from their perspective re-investing in Rillet was a "very easy decision" after the company's growth in the past year.

The Bigger Bet on Agentic Finance

"Rillet's initial wedge is accounting, but ultimately they are reinventing the entire finance function," Bek told TechCrunch, adding that agentic finance could become "one of the largest application software opportunities of the AI era." Sequoia led Rillet's Series A last summer. That framing — agentic finance as a category — is what differentiates Rillet from earlier waves of accounting software. Legacy ERPs encode workflows in forms; Rillet encodes them in models that take direction in plain English and complete the close end-to-end. The EY alliance is the first proof point that the largest professional services firms see that shift as a threat and an opportunity at the same time.

The Competitive Frame

The competitive picture is unusual. The incumbents Rillet is replacing — Oracle's NetSuite, Sage, Microsoft Dynamics — are not standing still; they are all racing to bolt agentic layers onto their existing stacks. But the replacement cycle Rillet is benefiting from is being accelerated by the accountant shortage, not by feature gaps. Companies cannot hire enough controllers and staff accountants, so they are paying recurring software dollars for the first time to automate what was previously people work. That dynamic is what lets a Series C close in 48 hours without a deck or a process.

What to Watch Through Year-End

Three checkpoints follow. Rillet's next quarterly metrics update — likely timed to its Series C announcement in October — will disclose whether the EY alliance converts into named customer wins or remains a partnership announcement. The wider agentic-finance category will see at least one other AI-native accounting startup cross the $100M ARR threshold in 2027, validating or refuting Bek's "largest application software opportunities" framing. And the legacy ERPs will begin to ship agentic features of their own, forcing Rillet to either out-innovate on the agent layer or fight an integration war it cannot win alone.