Why we invested in Tallia

We’re delighted to announce our lead investment in Tallia, the AI-powered research and drafting platform built for professional tax advisers. Outward led the $4.5m seed round, with participation from the ICAEW, Portfolio Ventures, and angels from across the tax, legal and technology spheres.

Last week’s Autumn Budget was a good reminder of what tax advisers are up against. Within hours of the Chancellor’s announcement, clients wanted to know what a doubled bank surcharge, higher tax on savings and property income, or a new Pensions Tax Allowance meant for them. Every Budget sets off the same scramble, and the UK tax code has roughly quadrupled in a generation.

Advisers can lose up to two hours a day to research, at partner rates that routinely exceed £1,000 an hour. General-purpose AI hasn’t solved this. Frontier models still struggle to pass the Chartered Tax Adviser (CTA) exams, and they can’t offer the audit trail that tax demands. An adviser needs to know not just what the answer is, but where it came from and whether it still holds.

The incumbents haven’t closed the gap either. Research databases are available firm-wide in most practices, yet the heads of tax we spoke to kept telling us the same thing, that usage is low, and advisers go straight to source.

Tallia takes advisers from a client’s first question to a finished deliverable, with every claim traceable to legislation, HMRC guidance and case law. But this is, above all, a story about two founders we’ve had the privilege of getting to know over the past year.

We first met Jack and Alex in November 2025, only a few months after they had incorporated. What struck us immediately was how complete they were as a pair.

They met as teenagers on an Army scholarship and they work with the trust and shorthand of brothers. Jack went on to qualify as a Chartered Accountant and Chartered Tax Adviser, spending five years in tax at PwC and Deloitte; Alex continued onto the Army, rising to Captain and serving as a Royal Signals Technology Lead.

Those who had worked with Jack described him as sincere, straight-talking and deeply knowledgeable, and Alex’s former Army colleagues referred to him as deeply technical and instinctively entrepreneurial.

Over the months that followed – through demos, customer calls and more than a few long conversations about how tax advice actually gets delivered – we saw that partnership up close. Jack would explain exactly why a partner would or wouldn’t trust an answer; Alex would show us how the system had been built to earn that trust.

Once we saw Tallia’s research in action, the difference was obvious. Rather than retrieving isolated chunks of text, Tallia’s proprietary knowledge graph maps how legislation, reliefs, guidance and precedent relate to one another, so the model reasons over connected context. On a CTA Advanced Technical question, GPT-5 on its own scored 48%. With Tallia’s approach, it scored 93%.

Accuracy is only the foundation. Tallia covers the whole advisory workflow – research, drafting, review and export into a firm’s own branded deliverables. Teams using it save over five hours per fee earner each week. And when the Budget landed last week, Tallia was ready with a Budget Desk that answers questions straight from the GOV.UK documents.

If there is a single reason Tallia stands apart, it is the deep relationship with the ICAEW. Founded by Royal Charter in 1880, it is arguably the most recognised accountancy body in the world, with more than 211,000 members and students across 150 countries. It is also a founding member of Chartered Accountants Worldwide, a network of over 1.8 million chartered accountants.

The ICAEW chose Tallia as its partner to evaluate and deploy AI for the profession, and it has now invested alongside us. We know of no other AI company in tax with that combination of endorsement and alignment from the institution that sets the standard.

That is a huge leg up. It brings Tallia credibility with firms of every size, and a direct line to practitioners far beyond the reach of a typical seed-stage sales team. In a profession built on trust, that matters more than almost anything.

Accountancy is one of Britain’s great exports. The chartered accountant was a British invention, and every one of the Big Four traces its roots to Victorian Britain. Over the following century and a half, the UK took the profession – its qualifications, its standards and its firms – out to the rest of the world.

That makes the UK the natural place to build. London remains a global hub for professional services, and the relationship with a leading UK firm can open doors to its member offices around the world, just as ICAEW members carry the British standard to over 150 countries.

The timing is right too. Private equity now backs several of the UK’s top ten accountancy firms, bringing margin pressure and a mandate to invest in technology. And legal has shown that professionals will pay for AI built for their domain. Tax remains underserved by comparison.

Tallia sits squarely within one of Outward’s core themes: vertical AI for professional services. It joins Orbital in legal real estate and Capsa in private capital, and we’ve seen firsthand how these markets reward products that earn professionals’ trust.

Jack and Alex are building from a British beachhead towards something much bigger. More jurisdictions, deeper workflows and, in time, the platform the tax profession runs on. If you’re an engineer or commercial leader who wants to help build it, Tallia is hiring. And if you lead a tax team, we’d love to introduce you.

We’re proud to back Jack and Alex. Tax has waited long enough for AI it can trust.