Definely: How one blind lawyer inspired a $40m AI business

Nnamdi Emelifeonwu was a young associate at one of London's top law firms, when he noticed his visually impaired colleague struggling to navigate lengthy, multi-jurisdictional contracts. Rather than accept the problem as unsolvable, he set out to build a tool that would let his colleague, and eventually thousands of lawyers, work through complex documents without ever leaving Microsoft Word.

Today, Definely has raised around $40m, serves more than 150 customers including KPMG, Barclays and Slaughter and May, and has just been named a launch partner for Anthropic's "Claude for Legal". Speaking to Sir Richard Harpin on the Business Leader podcast, Emelifeonwu speaks candidly about validating the idea before quitting, the discipline of charging for early pilots and more.

In our interview, you will learn about:

• How Nnamdi validated Definely with 100 lawyers before he left his job
• The journey from a £150,000 angel cheque to a $30m Series B
• Why a new pricing strategy for pilots changed how customers engaged
• How Definely became a launch partner for Anthropic's "Claude for Legal"

From Lagos to a Magic Circle law firm

Nnamdi Emelifeonwu moved to the UK from Nigeria aged seven, having spent his early years with his grandmother while his mother, a nurse, and later his father, joined the UK to find work. "Not growing up with your mum and seeing her regularly teaches you to be a little bit tougher," he says.

Law was the practical choice in a Nigerian household. "You're either a doctor, an engineer, a lawyer, or you're lost," he jokes, and having ruled out maths and blood, law won by elimination.

He trained and qualified at Freshfields, where he met Fergus McDade, a few years his senior and one of the UK's few registered blind solicitors. Emelifeonwu watched Fergus lose hours simply trying to navigate the contracts both of them worked on. It convinced him that there had to be a better, more inclusive, way.

The pair built Definely to solve Fergus's problem first, only realising later that Emelifeonwu himself, and every lawyer like him, needed the same tool.

How to bootstrap an AI platform

Emelifeonwu refused to quit his job until he had proof. He spoke to around 100 lawyers while building the first prototype, testing the idea on the other side of live deals. "Until you have something that has been validated by users, you have to be careful," he says. A failed attempt to launch a Poundland-style retail business in Nigeria had already taught him the cost of moving too fast without evidence.

He funded the earliest development himself, then secured a £150,000 angel investment from his former boss, followed by a £1m seed round – all while retaining around 70 per cent of the company.

Definely's first two customers were Deloitte and Ashurst, a deliberately top-down approach to enterprise sales rather than starting small.

Early on, Emelifeonwu insisted customers pay for pilots. "When they do pay, they take things more seriously because they've spent money and committed to it," he says, adding that he would only remove the charge once the product had proven itself with a base of paying customers.

The decision to build Definely as a tool that works inside the documents lawyers already use, rather than a separate platform, was, in Emelifeonwu's words, "everything".

Having spent five years drafting and reviewing in Word himself, he knew that anything requiring lawyers to leave that interface would struggle to gain adoption, however good the underlying technology.

That same insistence on what he calls "critical quality" extended to formatting. Definely's review tools had to display information that matched the source document exactly, with nothing altered. Technical advisers repeatedly told him it could not be done. "I said no, it must be possible," he says, "there's no way we're going to build this without it."

When Definely met Anthropic

With more than 150 customers and 80 staff, Definely now has a small commercial team in New York, deliberately staffed with Americans who understand the US legal market, alongside its product and technology base in London.

Emelifeonwu argues the UK remains an outstanding place to start a company, citing SEIS and EIS tax reliefs and the R&D credit scheme, but believes UK investors need to back ambition as boldly as their US counterparts do at Series A and beyond.

The rise of generative AI, he argues, has only sharpened the need for tools like Definely. As lawyers increasingly draft using AI, someone still has to catch what the AI gets wrong, which is why Definely has just become a launch partner for Anthropic's "Claude for Legal", building an MCP connector that lets Claude tap into Definely's review capability.

Nnamdi Emelifeonwu's four lessons for leaders

Validate before you leap. Emelifeonwu spoke to around 100 lawyers and kept his job until he had demand, a discipline he credits with saving him from repeating an earlier failed venture in Nigeria.

Make pilots pay. Charging customers from the outset, even a small amount, filters out lukewarm interest and forces both sides to take the process seriously.

Protect your core, but stay curious. Definely expanded its product range only after listening carefully to customers, resisting the temptation to build everything they asked for.

Cash is king. "You've got to make sure you're making revenue and watching your metrics," Emelifeonwu says. Scaling for growth's sake, without the fundamentals in place, is the fastest way to run out of road.

You can hear the full conversation with Nnamdi Emelifeonwu on the Business Leader podcast.