Studied tax law at the University of Applied Sciences for Finance of the State of North Rhine-Westphalia in Nordkirchen, followed by a role as a tax inspector within the North Rhine-Westphalia tax authorities.

In 1996 she was appointed as a tax adviser.

She has worked at one of the former Big Five accountancy firms, in the tax department of Allianz Versicherungs AG, and at various tax consultancy firms, most recently spending eight years as a partner.

Joining MOOG Partnerschaftsgesellschaft in Darmstadt in January 2026.

Ilona Aengenheyster specialises primarily in the preparation of annual accounts, the completion of personal and business tax returns, and providing ongoing tax advice.