HSP GRUPPE, a network of legally independent tax advisory, auditing and law firms, has embedded ChatGPT Enterprise into tax advisory, legal research, client communication, financial analysis and knowledge sharing across its network.
Rollout as organizational change
The firm treated the deployment as an organizational transformation focused on adoption, governance and continuous learning, rather than a simple software rollout. Monthly AI forums were established for staff to share use cases. HSP says ChatGPT Enterprises security features provide a technical foundation while client-related data use remains governed by the networks internal data protection and confidentiality rules. Professional review and final responsibility continue to rest with the relevant tax, legal or accounting specialist.
Tools, use cases and user experience
Employees rapidly discovered practical applications. HSP standardized successful approaches into shared Agents such as AI Client Communication, which helps draft and structure client-facing text, and Booking Assistant SKR03 & SKR04, which assists with booking questions. Partners report time savings and workflow improvements: Partner Magdalene Posnak said evaluating multiple real estate investments dropped from about nine hours to roughly two, allowing more client advisory time. Managing Partner Frank Heibel described ChatGPT as a “technical sparring partner,” and other leaders use AI-powered dashboards or ChatGPT to support—but not replace—professional judgment.
Adoption metrics and capacity effects
HSP reports that the usage figures refer to the shared ChatGPT Enterprise workspace used by HSP GRUPPE and Kanzleipakt, covering 81 organizational groups. Between Feb 1 and Jul 14, 2026, users exchanged more than 500,000 messages. During that period the workspace achieved 84% weekly active usage, with 755 weekly active users and 913 unique users. In surveys, 98.6% of employees reported higher productivity and 84.6% reported improved work quality; 95.9% reported weekly time savings, with 63.5% saving at least two hours and 25.7% saving at least five hours.
HSP estimates a conservative additional annual capacity of about 40,000 hours—approximately 28,000 hours for generally billable specialist work and 12,000 hours for administration and client service—and a theoretical annual revenue potential of about 3.8 million, noting this represents a capacity scenario rather than realized revenue. The organization is piloting ChatGPT Work to explore agentic automation of complex workflows and plans, together with Kanzleipakt, to form a DATEV-centric AI and development team. The firm expects to assess the full financial impact later this year.
Original source: OpenAI News