Allen & Overy

Global law firms face a fundamental productivity challenge: legal research and document drafting are labor-intensive tasks that demand precision across multiple jurisdictions, practice areas, and regulatory frameworks. For Allen & Overy — a firm with thousands of lawyers operating across 43 offices worldwide — the inefficiency compounds at scale. Associates and partners routinely spent hours manually reviewing case law, statutes, and regulatory materials before drafting. With billable time under pressure and client demands for faster turnaround increasing, the cost of slow, manual workflows was both financial and competitive. The firm needed a solution that could operate at enterprise scale without introducing accuracy risk.

Allen & Overy partnered with Harvey AI to deploy a large language model-based assistant firm-wide — becoming the first major global law firm to roll out generative AI at this scale. Rather than piloting with a single practice group, the firm took a full-deployment approach, making Harvey available to all lawyers across every office and jurisdiction. Harvey's platform covers legal research, document analysis, contract review, and drafting — integrating into daily workflows rather than requiring lawyers to adopt a separate research environment. The deployment spans diverse practice areas and legal systems, with Harvey's domain-specific AI trained on legal materials to support the precision requirements of professional legal work.

The deployment reached over 4,000 lawyers across 43 offices, making it one of the largest enterprise AI rollouts in the legal industry at the time. Allen & Overy reported meaningful time savings on research and drafting tasks, freeing lawyers to focus on higher-value advisory and strategic work. Key outcomes include:

• 4,000+ lawyers actively using Harvey AI firm-wide
• 43 global offices covered under a single deployment
• Reduced time spent on routine research and first-draft document work
• Established a replicable model for enterprise-scale AI adoption in professional services

• Full deployment beats cautious pilots — Allen & Overy's decision to launch firm-wide rather than restrict access to a test group accelerated adoption and normalized AI use across practice areas.
• Domain-specific AI matters in regulated industries — general-purpose LLMs carry accuracy risk in legal contexts; purpose-built platforms trained on legal materials reduce that exposure.
• Scale requires executive commitment — rolling out AI to 4,000+ professionals across 43 offices requires top-down sponsorship and change management, not just technical integration.
• Workflow integration is the adoption lever — embedding AI into existing drafting and research workflows reduces friction and drives consistent daily use.
• First-mover positioning carries reputational value — for professional service firms, leading on AI adoption signals capability and attracts clients prioritizing speed and innovation.