How HSP GRUPPE builds AI capabilities for tax advisory

HSP GRUPPE has embedded ChatGPT Enterprise across its network of tax advisory, auditing, and law firms to transform professional work processes, OpenAI said Thursday. The firm network achieved 84% weekly active usage with 755 weekly active users and 913 unique users over six months ending July 14, 2026, generating more than 500,000 conversations. CEO Carsten Schulz said the challenge was not introducing AI but helping the organization absorb it. HSP approached the rollout as an organizational transformation with monthly AI forums, governance requirements, and professional review standards. The network standardized successful use cases into shared custom Agents, including an AI Client Communication tool and a Booking Assistant for SKR03 and SKR04 accounting standards. Partner Magdalene Posnak reduced real estate investment evaluation time from nine hours to around two hours. Managing Director Marco Sell uses AI-powered dashboards for client scenario planning. HSP is piloting ChatGPT Work to explore agentic AI for continuous bookkeeping review and proactive document requests, aiming to redesign year-end accounting workflows rather than simply automate existing processes. The firm network estimates 40,000 additional annual hours of capacity across the organization. Schulz said the economic benefit focuses on redirecting saved time toward advisory work and client service rather than reducing headcount.