PIA Group, an international accountancy, audit and consultancy firm, is continuing its expansion in Luxembourg with the addition of ADC Group to its network. The firm, which has offices in Saint-Vith, Verviers, Weiswampach and Steinfort, becomes the group’s third member firm in Luxembourg, following Neoviaq and DTAX.lu.
ADC Group was founded in 1990 and provides family-run SMEs with accountancy, tax and advisory services. The firm has 31 staff members and six partners – Werner Müsch, Dirk Heinen, Micha Nilles, Raphael Ruess, Dylan Brülls and Corinne Breuer – who are also joining the PIA Group’s shareholder base. “ADC Group is a perfect fit for PIA Group. The firm combines deep local roots, a genuine culture of consultancy and a long-term vision,” says Steven Brouckaert, executive chairman of PIA Group.
Responding to changes in the sector
For ADC Group’s founder, Werner Müsch, this merger is a response to the changes taking place within the industry, particularly electronic invoicing via Peppol, automation and artificial intelligence, which are reshaping the sector. “Growth has never been an end in itself for us, but rather a means of continuing to deliver the quality of service our clients expect from us in the future,” he explains. Joining the PIA Group should enable the firm to draw on additional expertise and new investment capacity.
The teams remain in place
Clients continue to work with the same points of contact whilst gaining access to other services offered by the PIA Group, including legal advice, VAT, corporate finance, wealth planning and digital transformation. “Our principle is simple: to remain local where this creates value, and to work together where this makes us stronger,” summarises Nathalie Calle, CEO of PIA Group Belux.
Continued growth
ADC Group joins the group after the integration of five further firms since the start of the year. PIA Group was founded in Belgium in 1999 and now comprises more than 160 sites and 3,750 employees in Belgium, Luxembourg, the Netherlands and Germany. The group achieved a turnover of €440m in the Benelux in 2025.
