Thomson Reuters celebrates CoCounsel Milestone

Thomson Reuters has announced that CoCounsel, its professional-grade AI technology, now has over 1 million users. CoCounsel is now available in 107 countries and is used by legal, risk, compliance, tax, accounting, audit, and global trade professionals. The obvious conclusion is that Thomson Reuters is proving that it has moved from experimentation with AI to valued solutions that organisations have adopted. Sometimes in preference to the plethora of AI startups flooding the legal market, especially. Thomson Reuters’ competitive differentiation lies in its access to knowledge and data that others do not have, as it is not in the public domain.

The announcement led to a significant jump in the share price. As analysts seemed to perceive that the threat from new market entrants had receded, with Thomson Reuters cementing its position and likely to continue to grow. Shares rose by 11.41% from yesterday’s close of 91.00. Though they are still well below the 126.36 they were a year ago.

With a million users leveraging CoCounsel, Thomson Reuters believes its solution offers practical assistance to professionals within their daily workflows. In sectors where accuracy, sourcing, and data protection are essential.

Steve Hasker, President and Chief Executive Officer, Thomson Reuters, commented, “Professionals are not deciding whether to use AI anymore. They are deciding which AI they trust when their reputation and their clients’ data are on the line.

“CoCounsel is built for moments when being almost right is not good enough. It is grounded in decades of authoritative content, validated by domain experts, and backed by a clear commitment that customer data remains theirs. That is why one million professionals rely on CoCounsel.”

Why did the shares rise

CoCounsel is the Thomson Reuters solution that delivers AI capabilities across its portfolio. Existing solutions include CoCounsel Legal, CoCounsel Tax and Audit, and ONESOURCE+. However, several of these solutions are not yet deployed globally. For example, CoCounsel legal launched in the UK in January 2026 and has yet to be rolled out across Europe and other regions. It was launched in the US market in August 2025.

Importantly, CoCounsel Legal is not just backed by Westlaw content; it also leverages the Practical Law solution. That data is curated by a team of over 650 legal professionals to ensure it is accurate and fit for purpose. The risk associated with leveraging general-purpose AI is that its datasets may be flawed.

In the courtroom, the risk of unsubstantiated AI solutions is fraught. And Thomson Reuters, backed by decades of experience and knowledge, mitigates that risk, though the responsibility still lies with lawyers. To ensure that lawyers have surety the system evidences AI insights with citations that can be checked.

CoCounsel is also not a standalone solution; it integrates with other solutions commonly used by the legal or other professions. CoCounsel is just at the beginning of its growth; in time, it will support and enhance Thomson Reuters tools across multiple languages and countries. The opportunity is huge.

David Wong, Chief Product Officer, Thomson Reuters, said, “When the work matters, the AI must be professional grade. Professionals need systems that can complete sophisticated work within the standards they are accountable to every day.

“That’s the gap between CoCounsel and everything else. One million CoCounsel users across 100+ countries reflects a shared global consensus.”

Designed to succeed

The success of Thomson Reuters CoCounsel is not an accident. It has been designed carefully with governance in mind. It employs a multi-layered governance framework for developing AI solutions, centred on ensuring reliability, security, and ethical alignment across professional sectors such as legal, tax, and risk. A combination of internal ethical principles, human oversight, and board-level supervision drives this framework.

In addition, it has made several design decisions when creating CoCounsel, including:

• Licensed, authoritative content. Outputs are grounded in editorially enhanced legal and tax sources, not scraped public data.
• Expert validation. Domain specialists shape workflow logic and quality standards in areas where errors carry consequences.
• Workflow integration. CoCounsel operates inside research, drafting, and compliance platforms rather than as a standalone interface, enabling task execution within established professional systems.
• Data boundaries by design. Thomson Reuters does not repurpose customer inputs to train third-party models or generate outputs for other users.
• Multi-model architecture with governance. Thomson Reuters works with leading frontier models, including Anthropic’s Claude, OpenAI’s GPT and Google’s Gemini, alongside proprietary AI technology and structured datasets to maintain performance control and system-level oversight.

In legal, tax, audit, and compliance tasks, AI must find relevant sources, analyse data, apply legal rules, and produce review-ready results, requiring integrated systems. CoCounsel acts as an execution layer within professional platforms, using foundation models, proprietary AI, licensed content, and expertise to complete complex workflows.

What of the future

Beyond moving the solution beyond the US and UK, the next version of CoCounsel Legal is about to enter beta. It will support a natural language interface that will enable lawyers to describe an objective to Counsel. CoCounsel can then conduct the following steps:

• Build a plan
• Retrieve authority from Westlaw and Practical Law
• Search and retrieve relevant user documents and precedents
• Analyse the material
• Verify that citations remain in good law
• Finally, deliver structured work product within a single system

The next generation of CoCounsel Legal, entering beta soon, is designed around conversational task execution. Soon, legal professionals within law firms and corporations will be able to describe an objective as they would brief a colleague. CoCounsel will add additional next-generation capabilities within CoCounsel Tax and ONESOURCE+ late in 2026.

Enterprise Times: What does this mean

The use of AI within legal and other professions has reached a tipping point. While the human must remain in the loop, intelligent use of AI can supplement and automate many manual processes that people have historically handled themselves. As time passes, the fundamental question will be whether trust in these systems will grow and how much AI can support work that carries legal or financial consequences.

Moreover there are other questions associated with this. Thomson Reuters and other AI solutions will argue that responsibility for the decisions and evidence lies with the human, not the technology. At some point, there will likely be cases where humans have relied on technology too much.

Will humans be liable for errors in AI that they missed, or will the vendors behind the AI-powered solutions be responsible? With Thomson Reuters’ army of experts, mature AI solutions, and already 1 million users, Thomson Reuters is leading the way in a new reality where AI works alongside humans.

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