Rillet has opened a London office to enter the UK market, Korea IT Times reported, a move that matters broadly because it takes an AI-native challenger to established ERP providers such as SAP, Oracle and NetSuite, and matters specifically to accountancy professionals because Korea IT Times says Rillet has relationships with firms including EY and RSM.

Rillet is, according to Korea IT Times, a US-based accounting software company whose platform combines a real-time general ledger, continuous close and AI agents, serving nearly 1,000 customers in 75 countries, up from more than 600 when its Series C was announced in August.

EY is a Big Four accountancy firm and RSM is an accounting and consulting firm, both named by Korea IT Times as Rillet relationships.

Nicolas Kopp, Rillet’s founder and chief executive, said in the company’s announcement that finance teams in the UK were running on Rillet within a year of its US launch. Korea IT Times reported that Rillet says international net new annual recurring revenue more than tripled month over month, and that the London office will handle sales, implementation and customer services.

The funding backdrop is large. TechCrunch reported a 100 million dollar (about 88 million euros) Series C led by Iconiq at a 1 billion dollar (about 880 million euros) valuation, and said Rillet’s growth included an alliance with EY.

The control question is the accounting point. Fintech Global reported that Rillet’s AI agents operate inside the ledger with audit trails and human sign-off where required, while Korea IT Times noted the company has not disclosed independently verified figures on cost or close-time savings.

Korea IT Times also said replacing a core accounting system means migrating records, validating controls and integrating applications, which are tasks accountants and auditors usually handle. That last point is my own reading, not stated by Korea IT Times.

Korea IT Times said European businesses operate across different tax regimes, accounting practices and regulatory jurisdictions, so implementation partners may matter as much as the software.

For the sector, an AI-native ledger vendor arriving with accounting-firm relationships shows software and advisory work being sold together, with accountants shaping how AI is controlled in financial records.