Building your legal AI
evaluation checklist
A practical checklist for evaluating legal AI — from accuracy and security to workflows, adoption and value.
Wherever you are on this, these are the questions worth asking.
Some firms are still weighing up whether to move at all. Others have Copilot running in their Microsoft environment and think legal AI is covered. Some are mid-trial with a platform. A few have had something in place for a year and are quietly wondering whether they chose right.
All of those firms have something in common. The questions in this checklist are useful to them. Not because they are all at the same point, but because good legal AI decisions are made by asking the same fundamental things, regardless of starting point.
This checklist is published by LexisNexis. We think Lexis+ with Protégé is the right answer for most UK legal teams. But the framework here is designed to give you genuinely useful questions, and our evidence appears as proof that those questions have good answers, not as a sales pitch.
First: what should legal AI actually do?
Before you can evaluate any platform, you need a benchmark. Legal AI that earns its place in a law firm or in-house team does three things well.
It is grounded in authority
A response about a section of the Companies Act 2006 should draw on the statute itself, current case law, and authoritative commentary. Not a confident paraphrase of whatever appeared highest in a web search. For UK legal work, that means the platform draws on verified sources including Halsbury's Laws, validated case law, and current legislation updated after Royal Assent.
It produces work you can stand behind
The output has to be accurate enough to use, or accurate enough that the correction time is genuinely less than doing it from scratch. Citations have to be checkable. Drafts have to be legally sound. If you cannot verify where an answer came from, you cannot use it in front of a client, in court, or in a board-level advice note.
It fits into how your team actually works
A tool that requires lawyers to leave their document management system, log into a separate platform, and copy text between windows will not be used consistently. The friction compounds. The platform has to sit close enough to existing workflows that using it is less effort than not using it.
"Lexis+ AI provides swift and accurate answers to complex legal questions, saving significant time."
Roger Evans
Barrister
Harcourt Chambers
The evaluation checklist
These questions apply whether you are evaluating a new platform, reviewing what you already have, or trying to decide whether a trial is worth taking further. Work through each theme and be honest about the answers.
1. Content and accuracy
This is where most platforms differ, and where that difference matters most.
- What authoritative UK legal sources does the platform draw on? Ask for a full content inventory, not just headline claims.
- How quickly is legislation updated after Royal Assent or commencement? For UK legal work, 24 hours is a reasonable standard.
- Are AI responses grounded in retrieved authority, or generated from training data with sources referenced afterwards?
- Does the platform validate citations in its own output, and flag where a reference cannot be verified?
- Can it handle jurisdictional distinctions between England and Wales, Scotland, and Northern Ireland accurately?
- Test it on a real matter. Not a vendor demo. Use your own documents, your own queries, and your own quality standard.
72% of UK lawyers feel more confident using AI that’s grounded in legal sources
A note on general AI tools
Microsoft Copilot and similar tools that run within your existing software suite are useful productivity tools. They are not legal AI. They are not grounded in authoritative UK legal sources. They are not built to the professional standards that legal advice demands. If your answer to 'do we have legal AI' is 'we have Copilot', this checklist is particularly worth completing.
2. Security and data protection
The security conversation will happen. Better to lead it than to have it after you have committed to a platform.
- Does the vendor have zero-retention arrangements with all foundation model providers? Your prompts and documents must not be used to train any large language model.
- Where is UK customer data stored? Data residency within the UK or Europe is a standard professional requirement.
- What encryption standards apply? AES-256 at rest and TLS 1.2 in transit are current baselines.
- What SOC 2 audit coverage exists? Ask for the current report, not just a confirmation that one exists.
- Can administrator controls restrict access, disable features, or manage permissions at an organisational level?
- Ask directly: does the vendor use customer data to train or fine-tune their models? Get the answer in writing.
3. Workflows and integration
A platform that only responds to individual prompts is limited. A platform that connects tasks into repeatable processes is a different proposition.
- Does the platform support multi-step workflows, or only single prompt-and-response interactions?
- Can you build, save, and share your own workflows across your team?
- Does it integrate with your document management system? iManage, NetDocuments, and SharePoint are the most common in UK practice.
- Can it switch between legal AI (grounded in authoritative sources) and general AI (for correspondence, summaries, and everyday tasks) within the same environment?
- How does it handle UK-specific practice area requirements? Test it in your key areas.
AI adoption is high
Yet integration into existing processes is low
17%
of lawyers said AI is integrated in their existing processes.
4. Adoption and support
The best platform is the one your team will actually use consistently. Adoption is a product quality question, not just a change management question.
- How long from contract signing to productive use? What does the onboarding process actually involve?
- Does the vendor's customer success team include legal professionals, or only technical account managers?
- What training materials and prompt guidance are available for new users?
- Does the vendor provide usage data so you can track whether adoption is working?
- Can you speak to references at firms of comparable size and practice profile?
5. Value and cost
The pricing structure matters more than the headline number.
- Is pricing per seat, per matter, or usage-based? Each has different implications depending on your volume.
- What costs typically appear after the initial proposal? Ask specifically about implementation fees, playbook creation, and overage charges.
- What is the minimum commitment, and what happens if you need to scale up or down?
- Have you modelled what the platform is worth to your firm? See the ROI calculator below.
If you already have a platform in place
The evaluation checklist above applies to what you have now, not only to what you might choose next. If you already have legal AI deployed, these additional questions are worth working through honestly.
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Is it being used on eligible work? |
Track the ratio of AI-assisted work to total work in your target areas. Login rates are not a measure of adoption. If the tool is only used occasionally on high-volume, recurring tasks, the deployment is not working. |
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Do users trust the output? |
If lawyers are routinely re-checking AI responses from the beginning rather than reviewing and refining, the accuracy question has not been resolved. This is a content quality issue, not a user behaviour issue. |
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Can you verify what it draws on? |
If you cannot trace a response back to a source, you cannot defend it in a professional context. Ask whether your current platform produces verifiable, citable output. |
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Has the security been properly reviewed? |
Many platforms adopted quickly during 2023 and 2024 were not subject to the security scrutiny that standard procurement would require. Apply the security checklist above retrospectively. |
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Is it keeping pace? |
The legal AI market has moved significantly in the last 18 months. A platform that was market-leading in 2023 may now be behind on workflows, content depth, or integrations. Evaluate against the current market, not against your original decision. |
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What is it actually costing you? |
Include the cost of time spent on workarounds, the cost of work the tool cannot do, and the opportunity cost of not having full-capability AI. The headline licence fee is rarely the full picture. |
Building a number you can defend
A legal AI platform is a budget decision. At some point you will need to present a number that justifies the investment to someone who is not a lawyer and does not share your instinct that this is the right move.
The strongest cases combine three things: current cost of the workflows AI will change, a conservative estimate of efficiency improvement, and a clear translation into financial terms. Not just hours saved. Hours saved converted into recoverable capacity, reduced external counsel spend, or avoided recruitment.
What UK legal teams have reported
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Specific matters: avoided external advice cost of between £500 and £1,000. Weekly time saving per engaged user: 1.5 to 5 hours. |
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Resource equivalent value across the team: approximately £50,000 to £60,000 per year. |
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Statutory clause check: from 10 to 15 minutes to under one minute. |
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Structured 30-user pilot. Average saving: approximately 30 minutes per user per week. |
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Platform usage rose four times in month one and five times in month two of rollout. |
What a good decision looks like
A good legal AI decision is not necessarily the one that picks the most feature-rich platform. It is the one made with honest answers to the questions above, a clear understanding of what the team actually needs, and a realistic plan for getting people to use it consistently.
The firms and teams that get this right tend to do three things. They test against real work, not vendor demonstrations. They resolve the security and data questions before they become obstacles. And they name a specific person who is responsible for making it work.
If your answers to the checklist above reveal gaps in what you have now, or point towards a different choice, the next step is a structured evaluation against a shortlist of platforms. If you would like to see how Lexis+ with Protégé performs against this checklist, contact your LexisNexis account team or take a look at our Lexis+ with Protégé page.
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