HSP GRUPPE, a network of legally independent tax advisory, auditing, and law firms, has shared usage figures and insights regarding its deployment of ChatGPT Enterprise across a shared workspace with Kanzleipakt covering 81 organizational groups. Rather than treating AI merely as an individual productivity tool for tasks like writing emails, leadership approached the rollout as an organizational transformation embedded into tax advisory, legal research, client communication, and knowledge sharing. Governance, data protection, and continuous learning were central to the strategy, with monthly AI forums allowing employees to share practical use cases. Professional review and final responsibility consistently remain with human specialists. Usage data gathered between February 1 and July 14, 2026, showed 84% weekly active usage, 755 weekly active users, 913 unique users, and over 500,000 exchanged messages. Survey results indicated that 98.6% of employees experienced higher productivity, 84.6% saw improved work quality, 79.7% reported better client service, and 78.1% noted higher job satisfaction. Furthermore, 95.9% reported weekly time savings, with 63.5% saving at least two hours per week and 25.7% saving at least five hours. HSP estimates a conservative theoretical annual capacity increase of approximately 40,000 hours, equating to a theoretical annual revenue potential of around €3.8 million based on capacity scenarios. Looking ahead, HSP is piloting ChatGPT Work with developers and administrators to explore agentic AI and automated end-to-end workflows, such as continuous bookkeeping reviews. Together with Kanzleipakt, the network plans to establish a joint DATEV-centric AI and development team to scale successful decentralized experiments into standardized reference workflows.
How HSP GRUPPE builds AI capabilities for tax advisory
Tax advisory and law firm network HSP GRUPPE has integrated ChatGPT Enterprise across 81 organizational groups to transform its operating model. Over a six-month evaluation period, the firm tracked high adoption rates, significant time savings, and measurable productivity boosts. Leadership emphasizes treating AI as an organizational capability rather than a simple productivity tool.
Why it matters
This case study demonstrates how professional service firms can move beyond isolated AI experiments to integrate generative tools into core operating models and multi-step workflows. It highlights how governance, continuous learning, and human professional oversight enable scalable enterprise AI adoption without reducing headcount.
Topic dossiers OpenAI