Ernie Svenson had used ChatGPT before he moved to Claude. His explanation is the most honest sentence yet written about Claude for lawyers: “I hadn’t switched because ChatGPT failed me. I switched because I finally saw what I’d been missing.” What he had been missing was not a nicer paragraph. It was file access: Cowork, the mode in which Claude opens a folder on your machine and works through it (Attorney at Work).
Nobody chooses Claude for prose. Lawyers choose it because it reads a 300-page bundle in one go, keeps a playbook in memory, writes real tracked changes into a .docx and, on the right plan, keeps client material out of a training set. Anthropic says legal is the number one power-user job function in Claude Cowork, “with over three times the usage of any other function” (Mark Pike, Anthropic, in Artificial Lawyer).
Two facts sit underneath this, and most guides skip them: since 28 August 2025 the consumer plans train on your chats unless you opt out, and United States v. Heppner, the privilege case every ethics seminar cites, involved consumer Claude.
Why lawyers switch: file access and long documents, not prose
The most-read lawyer post of 2026 came from Zack Shapiro of Rains LLP, a two-lawyer firm, on 27 February; Artificial Lawyer put its views above seven million. Its centre is a closing-night story: a 40-page counterparty redline arrives at 7pm; by 11pm he has counter-language, tracked changes attributed to his own name and a client email, “Total time… under an hour, of which about 30 minutes is my own thinking” (Shapiro on X).
Three capabilities explain the switch stories:
- Folder access. Cowork is, in Shapiro’s words, the mode where “I point Claude at a folder on my computer, give it a task, and it goes and does it… the mode most lawyers haven’t tried”.
- Long documents. Opus 5 has a 1M-token context window “as both the default and the maximum”: a data room, not a clause. Anthropic’s own documentation adds that “more context isn’t automatically better”, so feed it the relevant bundle, not the whole matter.
- Abstention. In Chroma’s context-rot tests Claude models tended to abstain when uncertain; Pike said of Opus 4.8 that “you can feel it in practice as the model flags uncertainty instead of papering over it”.
Three modes: Chat, Cowork, Code
Artificial Lawyer’s analogy: Claude is the brain, Cowork the hands, Skills the recipes and a plugin the cookbook.
| Mode | What it is | Typical lawyer use | Watch out |
|---|---|---|---|
| Chat | The conversation window (web, desktop, Word) | A clause, a client email, a research skeleton | Starts from nothing unless inside a Project |
| Cowork | Works through a folder and writes files back | Chronologies, redline-to-response, batch NDA triage | Anonymise the folder first; check every file it touched |
| Code | A terminal agent that builds software | Shapiro’s command-line tool that converts contracts to audio for his commute | Tools holding client data need IT review |
A Cowork task, written for an anonymised folder:
The folder holds the anonymised correspondence for a [commercial dispute] under [jurisdiction] law; parties are already [PARTY_A] and [PARTY_B].
For every document extract: date (ISO), author, recipients, type, a one-line neutral summary, whether it mentions [the delivery delay], and any admission, instruction or promise, quoted verbatim with the file name.
Write chronology.md (one line per document, sorted by date) and gaps.md (periods over seven days with no documents; dates that conflict with content, marked DATE UNCERTAIN).
Add no facts from outside the folder. List unreadable files rather than guessing.Read every “admission” in the source before it goes near a pleading; the model finds candidates, you decide.
Projects and Skills: encoding your judgement
A Project stores standing instructions and knowledge files, so every chat inside it already knows your jurisdiction, house style and safety rules. A Skill is a saved procedure for a recurring task. Shapiro: “The difference between a firm playbook and an individual lawyer’s encoded judgment is the difference between giving someone a recipe and teaching them how to cook.” His thesis in one sentence: “The entire gap between ‘AI is a toy’ and ‘AI changed my practice’ lives in the quality of your instructions.”
The set-up method Svenson and Anthropic’s plugins share is an interview. Svenson: “I had Claude interview me about my background, my preferences and how I work. I told it to ask me 40 questions. It did … The result was a master skill that now sits in my top-level prompt.”
You are helping me write a reusable Skill for [reviewing inbound NDAs for a SaaS vendor]. Interview me first, in batches of ten questions, up to forty: jurisdiction and governing-law defaults; who my clients are; positions I always take and ones I concede; escalation triggers; house style; how citations must be handled; what must never appear in an output.
Then draft the Skill with SAFETY RULES first (flag every citation [VERIFY]; never invent facts, dates or figures; leave [BRACKETS] for missing information; every output is a draft for a licensed lawyer's review), then the procedure, the output format and the anonymised knowledge files to add.
Under 600 words. No client names from our history.Two rules from the claudeforlawyers.com Project workflow apply: “Lead your custom instructions with the safety rules, not your bio”, and never put privileged client specifics into a shared firm-template Project, because on Team and Enterprise plans Project knowledge can be shared. The full set-up is in Claude Projects and custom GPTs for law firms.
Claude for Word: native tracked changes, in beta
On 11 April 2026 Anthropic released Claude for Word in beta, for Team and Enterprise plans only (Artificial Lawyer). Anthropic’s own example prompt is the use case: “What did the counterparty change, and which revisions are dealbreakers?”
Stephen Smith’s test on a 30-page document found styles, numbering and defined terms intact, and the part that matters: “every change Claude makes shows up as a native Word tracked revision. Deletions in red. Insertions in green.” His limits: prompt-injection risk from counterparty documents, no persistent chat history, no Enterprise audit logs yet.
Compare this document, the counterparty's markup, with our last draft [our_draft.docx]. Produce a table of every change, including deletions and moved text: Clause | Our language | Their language | Effect on us in one sentence | Severity (Dealbreaker / Significant / Minor / Cosmetic) | Recommended response (Accept / Counter with: [text] / Reject with reason).
Then list any tension their changes create with clauses they did not touch, such as a new cap that conflicts with an untouched indemnity.
Apply nothing yet. I act for the [customer]; governing law is [jurisdiction].Run Word’s own compare as well, and remember the Vals benchmark: redlining was one of the two tasks where lawyers beat every tool, 79.7% against Harvey’s 65.0%. The redline is a draft. Playbook design is in AI contract review against a playbook.
Claude for Legal: 12 plugins, 93 agents, and the common-law caveat
People conflate two releases. On 2 February 2026 Anthropic put a legal plugin for Cowork into research preview for paid users: playbook-based contract review, NDA triage, redlines with fallbacks. The next trading day Thomson Reuters closed down 15.7%, RELX 14.4% and Wolters Kluwer 12.7%. Artificial Lawyer called the plugin “basically just a very complex prompt”. Right; the point is that you can read it.
On 12 May 2026 came Claude for Legal proper, an open-source repository under an Apache 2.0 licence (github.com/anthropics/claude-for-legal). Per the README as it stood in September 2026, it contains:
- 12 practice-area plugins (commercial, corporate, employment, privacy, product, regulatory, AI governance, IP, litigation, legal clinics, law students, a builder hub) and 20-plus MCP connectors including iManage, NetDocuments, DocuSign, Ironclad, Relativity, Everlaw and Harvey.
- 93 named agents, 10 of them scheduled, behind commands such as
/commercial-legal:reviewand/litigation-legal:chronology. - A cold-start interview per plugin (10 to 20 minutes) that writes a practice profile every skill reads. The README: “Skipping setup is the single most common reason a skill produces generic output.”
- Guardrails you can inspect. The review skill refuses to run without a playbook, reads the title and exhibits before the body (“a 40-page MSA with ‘confidential’ throughout is not an NDA”), flags citations from model knowledge as
[verify], and labels everything: “Every output from these plugins is a draft for attorney review — not legal advice.”
Two criticisms are fair. Gaius notes the 12 plugins are “calibrated for common law”: US contract, employment and procedure. A German or Austrian lawyer gets the method and rewrites the positions. And the LinkedIn verdict from Ruli’s Bryan Lee and Isabel Bathurst that the plugin “is more engineer than lawyer friendly at the moment” is accurate: the commands live in Cowork and Claude Code, and the practice profile is a markdown file. Pike’s advice covers both: “Don’t use it out of the box… it’s at its best when you customize it with your own legal playbooks.” When to let one run unattended is in what is an AI agent for lawyers.
Freshfields, Quinn Emanuel and the paralegal at counsel’s table
Now the other column. In Concord Music v. Anthropic (N.D. Cal., May 2025) a Latham & Watkins associate asked Claude “to provide a properly formatted legal citation”; the link was right, the author and title wrong, and the “manual citation check did not catch that error”. In Beus Gilbert v. BYU (D. Utah, September 2026) Claude was among the tools behind a $3,000 sanction.
Confidentiality: consumer plans train by default; Team and Enterprise do not
The single most important distinction in any Claude guide is consumer tier versus commercial tier. Anthropic changed its consumer terms on 28 August 2025 (Anthropic).
| Plan | Training on your chats | Retention | Notes |
|---|---|---|---|
| Free, Pro, Max (including Claude Code on these plans) | On by default; toggle in Privacy Settings | Five years if you allow training; 30 days if you opt out | Incognito chats not used for training; flagged chats kept 2 years |
| Team, Enterprise, API, Claude Gov | Off by default | API data deleted within 30 days; Enterprise admins set retention (minimum 30 days) | Thumbs-up/down feedback stored up to five years unless admins disable “Rate chats” |
Two details change behaviour. The opt-out is not total: Anthropic’s privacy policy (effective 10 September 2026) says that “even if you opt-out, we will use Inputs and Outputs for model improvement when: (i) your conversations are flagged for safety review … or (ii) you’ve explicitly reported the materials to us”. And “no training” is not “no human eyes”: never press thumbs-up on a client document, and switch off “Rate chats” in Organisation settings.
If you are on Pro today: Settings > Privacy > switch off “Help improve Claude”, or use Incognito. Then move client work to Team. The comparison with OpenAI, Google and Microsoft is in is ChatGPT confidential for lawyers.
EU data residency: only via Bedrock or Vertex
On Anthropic’s first-party API the inference_geo setting accepts “global” (the default) or “us” (at 1.1 times the price); there is no EU option, and “us” is “the only available workspace geo” for storage at rest (Anthropic documentation). EU processing exists through AWS Bedrock or Google Cloud Vertex regional endpoints, where the hyperscaler is the processor. Inside Microsoft Copilot, “Anthropic models are currently excluded from the EU Data Boundary”.
For a German or Austrian firm the route is Bedrock or Vertex in an EU region, or a European platform built on Claude; the § 43e BRAO contract must be signed by whoever is actually the processor. Details for all four vendors are in EU data residency for ChatGPT, Claude and Copilot.
Pricing tiers and which one a firm needs
| Tier | Price (September 2026) | Trains by default | Claude for Word | Who it suits |
|---|---|---|---|---|
| Pro | $20 a month ($17 annual) | Yes, unless opted out | No | Learning on non-confidential material |
| Max | From $100 a month | Yes, unless opted out | No | Heavy personal use; still consumer |
| Team Standard | $20 a seat annual, $25 monthly | No | Yes (beta) | The default for client work |
| Team Premium | $100 annual, $125 monthly | No | Yes (beta) | Cowork-heavy users |
| Enterprise | Custom | No | Yes (beta) | Custom retention, SCIM, audit logs |
Prices are Anthropic’s published figures. The innovation-committee lawyer who posted the r/legaltech pricing thread put the trade-off honestly: on Claude Cowork “$20 is fine, but the real tier is $200, and it’s still not a legal tool”, conceding that “for a solo lawyer this may be good enough”. For most firms under 50 lawyers the answer is Team, with consumer plans banned for client material. The wider comparison is in best AI tools for lawyers and the tools hub.
Limits and criticisms of Claude for lawyers
The strongest critique came in that same thread: “the ‘legal skills’ are basically system prompts + tool calling. That’s not legal reasoning.” True, and you know it because the prompts are on GitHub. Noah Waisberg of Zuva turned the open-source virtue into a warning: “as you invest more and more into your Claude prompts and workflows, what you’re building starts to look a lot like software… except without the QA, the versioning, the user feedback loops, or the ability to survive someone leaving the firm.” A two-person firm can live with that; a 40-lawyer firm needs an owner, a version number and a “last tested” date for every Skill.
Where to go next: the head-to-head is in ChatGPT vs Claude for lawyers; the Shapiro model of a firm built on skills is in AI-native law firms explained; ready-to-paste tasks for Cowork and Projects are in the prompt library. In AI Lab for Lawyers we build a Project and a first Skill live, with Cowork open on screen and anonymised precedents in the folder, so you leave with a working assistant rather than a demo.
Frequently asked questions
Is Claude better than ChatGPT for lawyers?
Neither is better on every task. Lawyers who moved to Claude usually cite file access (Cowork opens a folder and works through it), long-document handling and native Word tracked changes, not writing quality. ChatGPT scored 80% on Vals' October 2025 legal research test, per LawNext's write-up, and has Deep Research. On confidentiality the two are alike: the business tier is what matters, not the vendor. Try both on three real, anonymised tasks before choosing.
Is Claude confidential for legal work?
On Team, Enterprise and the API, Anthropic does not train on your inputs by default and deletes API data within 30 days. On Free, Pro and Max, chats train the model unless you switch off Help improve Claude, and opted-in data is kept for up to five years. In United States v. Heppner (S.D.N.Y. 2026) a defendant's consumer-Claude exchanges were held to be neither privileged nor work product. Client material belongs on a commercial plan.
What is Claude Cowork?
Cowork is the mode in which you point Claude at a folder on your computer, give it a task and let it work through the files, producing documents rather than a single chat answer. Anthropic describes it as Claude Code for non-coding work. Zack Shapiro called it the mode most lawyers have not tried. It is where the legal plugins install, and where Skills, your saved instructions for recurring tasks, run.
What are the Claude for Legal plugins?
Claude for Legal, released on 12 May 2026, is an open-source GitHub repository of 12 practice-area plugins (commercial, corporate, employment, privacy, litigation and others) plus 20-plus MCP connectors to tools such as iManage, NetDocuments, DocuSign and Relativity. Its README lists 93 named agents, 10 of them scheduled. Each plugin starts with a cold-start interview that writes a practice profile, and every output is labelled a draft for attorney review, not legal advice.
Does Claude offer EU data residency?
Not on Anthropic's own platform as of September 2026. The first-party API offers inference in global or US regions only, and workspace storage at rest is US-only. EU processing is available through AWS Bedrock or Google Cloud Vertex regional endpoints, where the hyperscaler is the processor. Inside Microsoft Copilot, Anthropic models are currently excluded from the EU Data Boundary. European firms should check this before choosing a plan.
Can Claude edit Word documents with tracked changes?
Yes, in beta. Claude for Word, released on 11 April 2026 for Team and Enterprise plans only, writes native Word tracked revisions and handles multi-level numbering, defined terms and cross-references. Reviewers report it keeps styles intact on 30-page documents. Limits noted in testing: prompt-injection risk from counterparty files, no persistent chat history and no Enterprise audit logs yet. Lawyers still beat AI on redlining in the Vals benchmark, so treat the redline as a draft.