Westlaw / LexisNexis
The two primary legal research databases Solicitors use to find case law, check current legislation, and research legal questions — the equivalent of a comprehensive law library accessible in seconds rather than hours.
What it is
About Westlaw / LexisNexis
Westlaw UK (Thomson Reuters) and LexisNexis UK are the two dominant legal research platforms, and together they contain virtually the entirety of English and Welsh law in searchable, citeable form. Both platforms index the same primary sources — cases reported in the Law Reports, the All England Reports, and specialist series; UK and EU legislation in consolidated form; and practice directions and procedural rules — but differ in their secondary content, user interface, and areas of particular strength. Westlaw UK is widely considered the stronger research platform for case law, with a search algorithm that returns results in relevance order and a Citing References feature that shows every subsequent case in which a decision has been cited, applied, distinguished, or overruled — an essential tool for verifying that a case on which you intend to rely is still good law and has not been undermined by a later decision. Its JustCite citator is the most comprehensive citation index in UK legal publishing, and its legislation service presents Acts and Statutory Instruments in their current consolidated form with amendment history annotated in the text. LexisNexis UK has historically been stronger in secondary commentary: its Halsbury's Laws of England database (the encyclopaedic statement of English law organised by subject area, updated continuously, and dating back to 1907) remains a uniquely authoritative starting point for researching an unfamiliar area of law. LexisNexis also has a stronger offering in some specialist practice areas — tax, financial services regulation, and property — and its Lexis Practice Advisor platform integrates practical guidance alongside the primary legal sources in a format that overlaps with Practical Law. Both platforms have introduced AI-assisted search features: Westlaw's AI assistant can analyse an uploaded document and identify relevant case law; LexisNexis has rolled out its Lexis+ AI platform, which allows natural-language questions and returns summarised answers with citations. These AI features reduce the time spent constructing Boolean search queries but introduce a verification obligation — AI-generated summaries of case law must always be checked against the primary source before being relied upon in a legal opinion or court document.
What you can do with it
Capabilities
Research whether a specific legal principle is still good law using Westlaw UK — finding the leading case on the issue (e.g. Caparo Industries v Dickman [1990] for the negligence duty of care test), opening the case in Westlaw, checking the Citing References panel to see every subsequent case that has cited Caparo, filtering by "Distinguished" or "Overruled" to identify any later Supreme Court or Court of Appeal decisions that have modified the principle, and confirming whether the principle remains as originally stated before relying on it in a legal opinion
Find current consolidated legislation in Westlaw — searching for the relevant Act (e.g. the Landlord and Tenant Act 1954), opening the current version of the statute, reading the consolidated text with all amendments from subsequent legislation incorporated in context (shown as annotations indicating which Act introduced each amendment), and confirming the operative version of a specific section rather than relying on an unannotated version that may not reflect recent amendments
Use Halsbury's Laws of England on LexisNexis to understand an unfamiliar area of law before conducting primary research — searching for the relevant title (e.g. "Landlord and Tenant"), reading the encyclopaedic narrative statement of the law with its commentary on leading cases and legislative provisions, identifying the key cases and statutes, then moving to primary source research in Westlaw armed with the conceptual framework that Halsbury provides
Conduct a Boolean keyword search in Westlaw to find cases on a specific fact pattern — constructing a search using field restrictions (e.g. "restrictive covenant" AND "legitimate business interest" AND "garden leave" in the judgment text, filtered to Employment Appeal Tribunal and above, last 10 years), reviewing the results in relevance order, reading the headnotes and judgments of the most relevant five cases, and building a case analysis schedule summarising the facts, ratio decidendi, and relevance to the current matter
Use Westlaw's Citing References to build the authorities section of a skeleton argument — starting from the primary cases already identified, using Citing References to find all Court of Appeal and Supreme Court decisions that have subsequently applied those cases to similar facts, identifying any cases where the court's reasoning more closely matches the current facts than the original authority, and compiling a finalised list of authorities with citations in the correct format for the court's practice direction
How to learn it
Learning Resources
Westlaw UK training (legalsolutions.thomsonreuters.com/en/training) — Thomson Reuters offers free online training for Westlaw UK including recorded tutorials and live webinars covering search construction, the citator, legislation research, and the AI tools; typically available to all subscriber firms and accessible to law students via their institution
LexisNexis training (lexisnexis.co.uk/products/training) — LexisNexis provides comparable training resources including Halsbury's-specific guides, practice area onboarding, and AI tool training; new subscribers receive implementation support
BAILII (bailii.org — free) — BAILII is the free public database of UK case law and legislation; using BAILII for personal research before subscription access is available builds the same search skills (understanding citation formats, navigating judgment structure, identifying ratio versus obiter) that transfer directly to Westlaw and LexisNexis
Law school legal research training — virtually all UK LLB and GDL programmes include at least two dedicated sessions on Westlaw and LexisNexis research; the LPC and SQE preparation courses cover legal research as a core skill assessed in the SQE2 practical assessments; this institutional training is the most structured introduction to both platforms
Pro Tip
The most common legal research mistake is confirming that a case exists and states what you think it states — but not checking whether it is still good law. Always run the Westlaw Citing References check (or the LexisNexis case citator) before relying on any case in a legal opinion, letter to a client, or court document. A case can be good law when you find it and overruled by a Supreme Court decision a year later; if you haven't run the citator, you don't know. This is not optional due diligence — it is the minimum standard of competence.
Skills that use this tool
Roles that use this tool
Alternatives