Only 11% of AI-Using Legal Teams Pick Claude. Here’s What the Rest Use
October 12, 2026 • 6 MIN READ
TL;DR
- 44% of general counsel say their legal teams now use generative AI, up from 28% a year earlier (FTI Consulting and Relativity, The General Counsel Report 2025).
- Among in-house legal teams that already use AI, 11% use Claude. ChatGPT is at 74% and Microsoft Copilot at 40% (Counselwell and Spellbook, 2025 benchmarking report).
- Most legal teams start with the general tools they already have. The tool matters less than the rules you set around client data and review.
You may have seen headlines suggesting that Claude has taken over corporate legal departments. The published surveys tell a quieter story, and I think it is a more useful one for a firm deciding what to do next.
What the surveys actually say
The General Counsel Report 2025 from FTI Consulting and Relativity surveyed more than 200 general counsel in a dozen countries. 44% said their legal teams are using generative AI, compared with 28% in 2024 and 20% in 2023. That is real growth, but it also means more than half of the legal departments in that survey were not using it yet. (FTI Consulting press release, March 26, 2025)
The second number comes from the AI in Legal Departments 2025 Benchmarking Report by Counselwell and Spellbook, which surveyed 256 in-house legal professionals, most of them in Canada. 38% of respondents were already using AI tools. Among those users, ChatGPT was the most common at 74%, followed by Microsoft Copilot at 40%, Spellbook at 22%, Gemini at 17% and Claude at 11%. (LawSites coverage, June 5, 2025)
So the honest version of the headline is this: about one in nine in-house teams that use AI report using Claude. The other 89% are mostly on ChatGPT and Copilot, often because those tools came bundled with something the company already pays for.
What the other 89% are using, and why
ChatGPT leads because it was first and most people tried it at home before they tried it at work. Copilot is next because it sits inside Microsoft 365, which most legal departments already run on. Legal-specific tools like Spellbook show up for contract work. Claude and Gemini are smaller slices.
The same report found that contract drafting, review and analysis is the top use (64% of AI users), followed by legal research (49%) and document translation (38%). Those are tasks where a lawyer still reviews every output, which is the right way to start.
The concerns lawyers keep raising
In the Counselwell and Spellbook survey, 60% of respondents named lack of trust in AI output quality as their top challenge, and 57% named data privacy. Only 7% of departments track the value of AI with specific measures. Those numbers match what I hear from firm owners: the worry is less about which brand to pick and more about what happens to client data and who checks the work.
What I would do if I ran a small legal team
- Write down your data rules first. Decide what client information may never go into an AI tool, and check each vendor’s business terms on data retention and training before anyone uses it on real matters.
- Start with one repeatable task. NDA review or first drafts of routine letters are good candidates. Keep a lawyer reviewing every output.
- Use what you already have before you buy something new. If you run Microsoft 365, test Copilot. If you want to try Claude or ChatGPT, use a business plan, not a personal account.
- Measure something simple. Track hours spent on the task before and after for a few weeks. Most departments skip this step.
The AI Playbook for Law Firms
We are putting together a plain-English playbook for small law firms: which tasks to start with, the data rules to set first, and how to check the work. Join the waitlist and we will send it when it is ready.
Frequently asked questions
How many in-house legal teams use Claude?
In the Counselwell and Spellbook 2025 benchmarking report, 11% of in-house legal respondents who already use AI said they use Claude. ChatGPT (74%) and Microsoft Copilot (40%) were far more common. The survey covered 256 professionals, mostly in Canada, so treat it as a benchmark, not a census.
How many legal departments use generative AI at all?
The FTI Consulting and Relativity General Counsel Report 2025 found that 44% of general counsel say their legal teams use generative AI, up from 28% in 2024 and 20% in 2023.
What are legal teams using AI for?
Contract drafting, review and analysis is the most common use (64% of AI users in the Counselwell and Spellbook survey), followed by legal research (49%) and document translation (38%). Trust in output quality and data privacy are the top concerns.
Related: Why Frontier AI Labs Are Racing to IPO Before Regulation Arrives
By Mark Yegge
This is education, not a promise of results. Results depend on implementation quality, firm size, and market conditions. Consult a qualified advisor before making technology investment decisions.