How Thomson Reuters and Anthropic built an AI that lawyers actually trust

Thomson Reuters is bringing AI to lawyers and tax professionals in a big way. The company has partnered with Anthropic to use its Claude AI technology across its professional tools, marking one of the largest AI rollouts in the legal industry.

At the heart of this initiative is CoCounsel, Thomson Reuters’ AI platform for legal and tax professionals. The system runs on Amazon’s secure cloud infrastructure, ensuring that sensitive client information remains protected while delivering AI-powered insights.

“We combine real expert human knowledge with advanced technology,” Joel Hron, Chief Technology Officer at Thomson Reuters, said in an exclusive interview with VentureBeat. “We have experts across many different domains generating content and workflows. For us, AI is a tool to facilitate the distribution of that expertise through our software.”

How Thomson Reuters built a legal AI platform using 150 years of professional content

The company has built a comprehensive retrieval-augmented generation (RAG) architecture that connects Claude to Thomson Reuters’ vast knowledge base, including content from over 3,000 subject matter experts and 150 years of professional publications.

Rob Greenlee, Head of Industries at Anthropic, explained the technical approach in an exclusive interview: “Claude’s foundation in understanding complex professional domains like law and tax comes from comprehensive training on a diverse range of high-quality texts, including professional and academic content. For work with Thomson Reuters, we’ve taken several additional steps… We then work closely with Thomson Reuters to optimize Claude’s performance through advanced prompting strategies and carefully designed workflows that leverage their authoritative content and domain expertise.”

Inside the strategic deployment of multiple AI models for professional services

Thomson Reuters is strategically deploying different versions of Claude based on task complexity. The company uses Claude 3 Haiku for rapid processing tasks and Claude 3.5 Sonnet for deeper analyses requiring detailed insights.

Early results show significant efficiency gains. “Customers are reporting transformative efficiency gains with CoCounsel,” Hron said. “Professionals are not only saving time but also elevating the level of work they focus on, maintaining quality while delivering more strategic value to their clients.”

Security remains paramount in the implementation. Amazon Bedrock provides what Hron called “a robust and battle-tested cloud infrastructure that adheres to our enterprise-grade security standards throughout the entire life cycle.”

Enterprise AI deployment sets new standard for security and professional trust

The collaboration between Thomson Reuters and Anthropic represents a new model for enterprise AI deployment, combining advanced AI capabilities with domain expertise and secure infrastructure. “What makes this partnership particularly valuable is the combination of Anthropic’s advanced AI capabilities with Thomson Reuters’ deep domain expertise and authoritative content,” Greenlee said.

Looking ahead, Thomson Reuters plans to expand its use of Claude, exploring agent frameworks for complex tax workflows and computer vision capabilities to help editorial teams curate content more efficiently.

“We’ve been vocal about our AI investment as a strategic part of our products going forward,” Hron said. “Our editorial workforce spends significant time building and curating content—we see tremendous potential to accelerate these processes with Anthropic’s computer vision and tool use capabilities.”

The implementation comes as law firms and tax professionals increasingly adopt AI tools to streamline their work. Thomson Reuters’ approach could serve as a blueprint for other enterprises looking to deploy AI while maintaining professional standards and data security.