Belgium’s Richest 50 Families Hold €85.5 Billion in Luxembourg
A joint investigation by Belgium’s leading newspapers has revealed that the country’s 100 wealthiest families hold a combined €91 billion in assets through 416 Luxembourg-based companies, with the top 50 families alone concentrating €85.5 billion. The findings, published on June 20 by Le Soir and De Tijd, represent a dramatic escalation from the 2018 “LuxFiles” investigation, which found €48 billion held by 60 families — a staggering 90% increase in just eight years.
What the Investigation Found
The data, based on non-public records from April 2026, shows that 64 of Belgium’s 100 richest families use Luxembourg entities for financial and tax structuring. According to The Brussels Times, these are overwhelmingly “mailbox companies” — entities with no staff or physical presence that share addresses with hundreds or even thousands of other firms in the Grand Duchy.
These structures are used to hold investments, cash, real estate, luxury goods, and shares in Belgian and foreign businesses. The combined €91 billion in assets exceeds Luxembourg’s entire annual GDP, underscoring the sheer scale of wealth being managed through the tiny European principality.
The Luxembourg Advantage
Luxembourg’s tax framework offers significant advantages over Belgium for holding companies. As The Brussels Times notes, profits from these holdings are not taxed, and beneficiaries pay only an annual subscription fee — a minimal charge compared to Belgium’s corporate income tax. There is no wealth tax on strategic participations and no withholding tax on certain dividend distributions.
This makes Luxembourg particularly attractive for family wealth management, succession planning, and holding passive investments. Among those named in the investigation is prominent Belgian investor Marc Coucke, who reportedly has four Luxembourg mailbox companies collectively holding over €130 million on their balance sheets.
A Growing Trend
The 2026 investigation is a direct follow-up to the LuxFiles investigation published by Le Soir and De Tijd in March 2018. That earlier probe found that 60 of the 100 richest Belgian families had created at least one company in Luxembourg, with combined equity of €48 billion. The current figures show not only more families participating (64 vs. 60) but also a near-doubling of assets under management.
This growth trajectory raises fundamental questions about whether existing tax rules are adequate to prevent wealth from being shifted to low-tax jurisdictions within the European Union itself.
Wealth Inequality in Belgium
The investigation lands at a particularly sensitive moment for Belgium. A study by Ghent University published in 2025 revealed that the richest 1% in Belgium possess the same amount of wealth as the bottom 75% of the population. Wealth inequality, which fell sharply during the 20th century, has stalled over the past 20 years.
Separate research by the National Bank of Belgium found that income inequality is higher than previously assumed, and that the wealthiest 1% contribute less in taxes and social contributions relative to their income. The bank noted that “this favourable treatment reduces the tax burden on top earners and drives inequality.”
Political Fallout
The revelations are likely to reignite Belgium’s debate over tax justice. The country’s new federal government — the “Arizona” coalition formed in early 2026 — has already introduced a 10% capital gains tax on share sales. Left-wing parties, including PVDA/PTB, have proposed a wealth tax of 2% on assets above €5 million and 3% above €10 million.
The investigation provides fresh ammunition for these proposals. The contrast between austerity measures affecting ordinary Belgians and the untaxed wealth of the richest families in Luxembourg could intensify social tensions and put pressure on the government to go further.
What’s Next
The findings also have implications beyond Belgium’s borders. The European Union has been scrutinizing Luxembourg’s tax practices for years, and this investigation adds pressure for EU-level action on mailbox companies. Questions remain about whether Belgian authorities will investigate these structures for potential tax avoidance or evasion, and whether the EU will push for tighter cross-border tax rules.
For now, the investigation offers an unprecedented window into the scale of wealth concentration among Belgium’s elite — and a stark reminder that, eight years after LuxFiles first lifted the lid, the flow of wealth to Luxembourg shows no signs of slowing.