SF's Rillet raised a $100M Series C led by ICONIQ at a self-reported $1B valuation — its third round in a year. The syndicate is real; the growth metric is "doubled new ARR," and there's no Form D under Rillet's name yet.

Rillet, a San Francisco company that sells software to automate a finance team's books, says it has closed $100 million in fresh capital and now carries a $1 billion price tag — its third raise in about a year and enough to enter the unicorn column. ICONIQ led the round, which Fortune reported first (external source, opens in a new tab) as an exclusive. Sequoia, Andreessen Horowitz and Oak HC/FT wrote checks again; new to the cap table are Bain Capital Ventures, Battery Ventures, FirstMark, Scale Venture Partners, Creandum and Sequoia Global Equities. ICONIQ's Seth Pierrepont takes a board seat.

The investor list is the solid part. Less solid is what the valuation rests on. The ten-figure mark is the number Rillet handed to reporters, not one drawn from a document. Pull the company's SEC EDGAR (external source, opens in a new tab) record and the two "Rillet" Form D filings that come back belong to FOG Ventures Fund III — a fund that invested, not the operating company disclosing its own offering. The raise itself has not surfaced in the filing record as of this week.

The traction figures come with the same asterisk. The company puts its customer count above 600, roughly triple a year ago, and says it doubled its new ARR in the quarter heading into the round. Read that phrasing closely: it is new ARR — the incremental bookings — not total revenue, which Rillet declines to give. Doubling new business is a genuine signal; it is not the same as doubling the company. The showcase account, per Rillet, is Mercor, said to be past $2 billion in ARR with a finance team of three — a customer's claim, passed along by the vendor.

Founder and CEO Nicolas Kopp has said publicly the deal came together in under 48 hours, on a round he wasn't planning to run — the familiar choreography of financing that investors chase rather than founders solicit. It lands on top of a $25 million Series A from Sequoia and a $70 million Series B, all inside a single year. The tests ahead are documentary: a Form D under Rillet's own name to stand behind the $100 million and the post-money, and a total-ARR figure to sit next to that customer count.