Diamant Software

Who owns Diamant Software?

Diamant Software is currently owned by Hg through Hg Mercury 4 (2023 vintage), since 2025.

Hand-verified · updated 2026-07-07

About Diamant Software

Diamant Software is a Bielefeld-based German software company whose Diamant/4 platform provides financial accounting, accounts payable and receivable management, controlling and reporting, and group consolidation for mid-sized organizations across the German-speaking region. It positions itself as a specialist for complex accounting and controlling requirements, serving healthcare and social institutions, public administrations, insurers, manufacturers and business associations, and increasingly emphasizes automation and what it calls agentic finance and controlling built on AI. The company employs more than 350 people at its Bielefeld headquarters and an AI competence center established in Darmstadt in 2019. According to its own disclosures, more than 100,000 users rely on its software, and press reporting placed annual revenue at over EUR 60 million.

Ownership journey

Diamant Software was founded in Bielefeld in 1980 and built its position over more than four decades as an independent, founder-led vendor of accounting and controlling software. In November 2025 Hg agreed to invest through its Hg Mercury 4 fund, taking a majority stake in a strategic partnership, with founders Peter Semmerling and Jan Semmerling remaining significant shareholders. Hg, one of the largest software investors in Europe, was presented as a long-term partner drawing on a multi-decade track record in the tax and accounting software sector. The investment is Hg's current holding in the business, which remains an active portfolio company with no exit or secondary transaction recorded.

Under PE ownership

The 2025 investment was framed around accelerating the development of Diamant's cloud software in the age of AI, enhancing customer service and strengthening its network of sales partners, while preserving continuity for existing users. It provides institutional capital and software-scaling expertise to a company that had grown organically under its founders to more than 350 employees and over 100,000 users. Because the partnership was only agreed in late 2025, operating outcomes under Hg's ownership are not yet visible in the public record. The stated priorities center on cloud migration, AI-driven automation of routine finance tasks, and expansion of the partner ecosystem.