London-based AI startup Tallia, formerly known as Revax, has raised €4 million ($4.5 million) in a Seed funding round. The company will use the funding to expand its AI-powered platform, which helps tax and accounting professionals with research and document preparation.

The round was co-led by Outward VC and the Institute of Chartered Accountants in England and Wales (ICAEW). Other investors included Portfolio Ventures, Expedite Capital, Paul Forster, Angus Miln and several angel investors.

“We are delighted to support co-founders Jack Mander and Alex Bartlam, building trusted AI systems for ambitious tax teams,” said Outward VC in a public statement.

Founded in 2025 by school friends Jack Mander and Alexander Bartlam, Tallia brings together their experience in tax advisory, engineering and technology.

The founders started Tallia to help tax professionals use AI to complete research and prepare documents faster while maintaining accuracy. They wanted to make sure that AI-generated work remains reliable and can be checked by professionals before being shared with clients.

Unlike general AI tools, Tallia is built specifically for tax and accounting firms. Its platform provides answers based on tax laws, government guidance and court decisions. It also links AI-generated answers to the original sources, allowing professionals to check the information before using it in their work.

Tallia also allows firms to connect their own documents, contracts, templates and previous work to the platform. This helps the AI use a company’s existing knowledge and follow its usual working methods when preparing research and documents.

The platform also includes review tools that allow senior professionals to check how the AI reached its conclusions and which sources it used. This helps firms maintain quality and ensure that important decisions remain under human supervision.