Amid a surge of legal AI tech firms coming to marker, concerns are emerging about ‘rented intelligence,’ with some companies criticised for simply putting their logos on technology developed by others. In contrast, Luminance insists it is focused on the bigger picture, betting its future on AI models it has built in-house.

Speaking to City AM, chief executive Eleanor Lightbody explained: “Having lightweight models that are your own models that are fine-tuned are really important, because fundamentally it means that your margins as a business are much more palatable and sustainable versus if you’re just renting off these frontier models.”

She stated that having a proprietary model allows firms to “stand out from the crowd” due to more “accurate results”, allowing the firm to “fine-tune your data”.

Luminance, founded by mathematicians from the University of Cambridge, focuses on the in-house legal departments at multinational companies.

Lightbody explained that when the legal tech business first started, it aggregated data from its customers with consent, allowing it to build its own models. With a blended approach, using rented tech alongside its own models, the company takes the “language that defines a business” in contracts and converts it into intelligence that the whole business can run on, and not just in the legal department.

The tech group launched ‘Luna’, a proprietary vertical AI model series purpose-built to help automate “low‑value, high‑volume” contract work so in‑house teams can advise on strategy, risk and opportunity instead of just firefighting or performing administrative tasks.

“We have our purpose-built agents that literally automate every single touch point that a business might have for the contract, so it automates the process of the starting with the creation of a contract all the way through to a negotiation of a contract all the way through to notifying businesses when there is key information within their contracts that they need to further review,” she explained.

Another of her examples is that Luminance is the “first company in the world” to deliver AI negotiating against AI on both sides of a contract, with a focus on NDAs. She stated that she doesn’t think “[lawyers] should ever be reviewing an NDA ever again” once the tech is properly in place.

The startup raised $115m over 12 months

The UK business has around 800 in-house customers using its “corporate” product. Currently, around 50 per cent of its revenue comes from the US, with a focus on growth in its key markets, as it offers potential clients a two-week free trial to try out its products.

The tech firm is fresh from raising $75m (£56.8m) in a Series C funding round, which, alongside its Series B, was raised within 12 months, bringing the total to over $115m (£87.2m). Its latest round was led by Point72 Private Investments, with participation from Forestay Capital, RPS Ventures and Schroders Capital, as well as existing investors including March Capital, National Grid Partners and Slaughter and May.

The legal tech industry is booming, with around $6bn raised by startups in 2025. Frontrunners like Harvey and Legora have absorbed a massive share of the capital as each tries to outdo the other in a marketing battle, the latest featuring actor Jude Law plastered across Legora’s billboards.

Lightbody stated that “this market has always been crowded… this is a very hot market, and I think that that is really demonstrative of how big an opportunity this is.”

There’s definitely much more money being poured into this market, but I think that that really validates what we’ve really believed to be true, which is this is something that is transforming the way in which in-house businesses are working… what we do, we feel slightly different is the fact that we have gone specifically after the in-house market,” she added.