Capital gains on shares: what the 2026 tax changes for your real estate company

What came into force

On 1 January 2026 Belgium introduced a tax on capital gains on financial assets, first presented as a "solidarity contribution". The general regime sets a rate of 10%, with an indexed annual allowance of 10,000 EUR that can rise to 15,000 EUR if left unused in earlier years.

That general regime will not be yours, however. If you hold a real estate company, you almost certainly fall under a different one.

The regime that concerns you: substantial participation

As soon as you hold at least 20% of the rights in the company whose shares are transferred, you fall under the "substantial participation" regime.

One point is regularly misunderstood: the 20% threshold is assessed per individual shareholder, not at family level, at the moment of transfer. Two spouses holding 15% each do not reach it. Among siblings, a brother holding 25% falls under it while a sister holding 18% stays in the general regime.

The regime applies explicitly to holding, management and real estate holding companies, not only to operating businesses. In other words, it targets you directly.

The scale is progressive, after the first tranche is exempt:

• First 1,000,000 EUR exempt
• 1 to 2.5 million 1.25%
• 2.5 to 5 million 2.50%
• 5 to 10 million 5%
• above 10 million 10%

Watch the periodicity: the first-million exemption is available once every five years, not annually.

What stays protected: the 31 December 2025 snapshot

This is the most important part of this article, and the most neglected.

Only gains built up from 1 January 2026 are taxable. The value of your shares on 31 December 2025 becomes your tax acquisition value. Twenty or thirty years of gain accumulated before that date stay out of the tax's reach.

But you must be able to demonstrate that value. For listed shares it is public and indisputable. For the unlisted shares of a real estate company, it is not: it has to be established, documented and defensible.

If you sell in 2027 or 2028 without a solid valuation fixed as at 31 December 2025, you will be arguing with the tax authorities about which part of the gain is historic and which part is taxable. That argument is prepared in advance, not during an audit.

Two traps worth knowing

Internal capital gains, taxed at 33%. If you transfer your shares to a company you control, directly or through family members, the rate is neither the general one nor the progressive scale: it is 33%. Exit structures through a personal holding are the direct target.

Transfers outside the European Economic Area, taxed at 16.5%. Where the buyer is an entity established outside the EEA, a single rate of 16.5% applies, with the first-million exemption still available. This extends a rule that already existed, and it is why a warranty on this point appears in any serious share transfer agreement.

What it actually changes for a seller

The share deal remains clearly better than the asset deal. Selling the buildings triggers corporate tax on the gain (25%), then withholding tax to get the proceeds out of the company, and leaves an empty shell to wind up. Selling the shares, with a first million exempt and a scale starting at 1.25%, is not comparable. The new tax rebalances at the margin; it does not reverse the logic.

Valuation becomes an exercise at two dates. Today's value negotiates the price. The 31 December 2025 value establishes the taxable base. These are two distinct calculations, and the second cannot be improvised retroactively.

Timing matters more than before. The million-euro exemption only replenishes every five years. For a family holding several companies, or siblings planning to sell at different moments, the order of operations is no longer neutral.

What to do now

• Have a documented valuation of your shares as at 31 December 2025 established, if that is not already done.
• Check who holds what, individually, to place each shareholder against the 20% threshold.
• If several transfers are envisaged, plan them across the five-year horizon of the exemption.