The accountants' institute backs an AI built to show its sources

The Institute of Chartered Accountants in England and Wales, or ICAEW, co-led a seed round for a company that sells software to research and draft tax advice, EU-Startups reported on 3 Nov 2026. Outward VC led alongside it, and Portfolio Ventures, Expedite Capital and several angel investors also took part. The company is Tallia, based in London, and its buyers are tax and accountancy firms and in-house tax teams. EU-Startups reports that it intends to use the money to expand adoption of its platform among those firms.

Tallia builds its pitch around checking the answer. It says its responses are grounded in tax authority guidance, legislation, and case law, and its line on checking them is "One click from claim to source." It says the system is trained and evaluated for tax advisers, that drafts are ready for partner review, and that the work runs from research through to memos, advice notes, and letters.

The product covers research, drafting, review, email and shared projects, the company says. Documents go through one structured, reusable grid, with a full audit log for every prompt, and Tallia says data put into it is never used to train models. EU-Startups reports that the software works across Microsoft Word, Excel, PowerPoint and Outlook, and that it connects to a firm's existing documents, contracts, templates and previous work. According to Tallia, as EU-Startups reported, a fully cited first draft takes an average of 30 seconds, and teams using the platform save an average of five hours per fee earner each week.

The legal entity, Revax Technologies Limited, was incorporated on 3 Jul 2025, and Tallia is its product. Jack Mander and Alexander Bartlam are the co-founders, and EU-Startups describes them as school friends. Mander is a Chartered Accountant and Chartered Tax Adviser with experience in M&A tax at Deloitte and PwC. Bartlam has an engineering background, experience leading technical systems in the British Army and technology policy studies at Cambridge.

Ostberg Sinclair & Co, a UK and US tax practice with offices in London and New York, has partnered with Tallia following a competitive pilot, Tallia says, and its advisers worked with the Tallia team to configure and test the platform ahead of deployment. It has rivals. Dealroom reports that Thomson Reuters and LexisNexis are adding AI to their tax platforms, and that Blue J and Fiscari, both AI-native, also offer answers with citations.

Filings show that Tallia raised £2.3m¹ in April 2026, in its first priced round. For scale, 618 independent UK companies first filed priced share issues at Companies House in October 2026, worth £1.65bn between them. The median was £0.4m.

¹ EU-Startups reported a €4 million seed round for Tallia on 3 Nov 2026.

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