German tax advisory giant HSP fully embraces ChatGPT, saving 40,000 hours annually

HSP GRUPPE, a network of independent tax advisory, audit, and law firms in Germany, is redefining how professional services operate through ChatGPT Enterprise. For over two decades, this network has continuously invested in the digitization and standardization of business processes, establishing a robust quality management system and a culture of continuous improvement long before the emergence of generative AI. When ChatGPT appeared, HSP's management did not stop at the level of "writing emails faster," but instead posed a more ambitious question: What happens when AI becomes part of the operational model of a professional service firm?

With this vision, HSP has deeply integrated ChatGPT Enterprise into core areas such as tax consulting, legal research, client communication, financial analysis, and knowledge sharing. CEO Carsten Schulz stated that the challenge lies not in introducing AI, but in helping the organization absorb and adapt to it. The company introduced monthly AI forums where employees shared practical cases, while internal data protection, confidentiality, and governance requirements were used to regulate the handling of customer information. Professional review and final responsibility always remained with the relevant tax, legal, or accounting experts.

From Efficiency Tool to Organizational Capability

HSP did not stop at encouraging employees to experiment; it aimed to build scalable organizational capabilities. The company standardized successful cases across its entire network and developed shared Agent tools, such as the "AI Client Communication" Agent, which assists in generating drafts, optimizing structure and tone, and the "Accounting Assistant SKR03 & SKR04" which supports preparing and categorizing specific accounting issues. These shared Agents reduce repetitive work while ensuring that best practices benefit every employee, not just AI experts.

The actual application results are impressive: Managing Partner Frank Heibel uses ChatGPT as a technical training partner to handle complex tax issues; Partner Magdalene Posnak reduced the time for evaluating multiple real estate investments from nine hours to about two hours; Director Marco Sell uses AI-driven dashboards to explore financial scenarios with clients during meetings. In the six-month evaluation period from February 2026 to July 14, employees exchanged over 500,000 messages with ChatGPT, with 84% of employees remaining active weekly, and 98.6% of surveyed employees reported an increase in productivity.

Redesigning Workflows with AI

HSP has begun exploring the next stage of agent AI applications using ChatGPT Work, expanding gradually after small-scale pilot tests. The company identified 88 opportunities for automation, but Schulz believes this number is too small— the real question is not how to automate existing processes, but how to redesign them. For example, in the traditional model, accountants often discover missing information months after completing bookkeeping when preparing annual reports. HSP is exploring making ChatGPT Work continuously review bookkeeping throughout the year, identify missing information, and proactively request documents from clients, so that a large amount of preparatory work is already ready before accountants even open the files.