Capital Gains Tax in Disguise
The Belgian government’s plan to introduce a new ‘Solidarity Contribution’ has sparked significant debate. Far from being a true act of solidarity, the measure adds burden without meaningful reform. In reality, it introduces a broad capital gains tax on financial assets, a major shift in Belgium’s taxation of private wealth.
Initially, the measure aimed to simplify and clarify existing tax rules, particularly those concerning abnormal wealth management, but political compromises removed most simplifications. What remains is an additional tax layer, on top of all existing ‘capital gains’ taxes, which increases complexity rather than reducing it.
Current Situation
Until now, Belgium taxed capital gains on shares only in limited cases (typically at 33%), such as speculative transactions or abnormal management of private assets. A 16.5% tax also applies when shares are sold to entities outside the European Economic Area (EEA) if ownership thresholds of 25% are exceeded.
The new capital gains tax will apply to gains realized outside of any business activities, specifically in the context of paid transfers (‘for consideration’) of financial assets that are part of normal private asset management.
New Regime
The new tax will cover capital gains from financial instruments such as stocks, bonds, derivatives (e.g. futures, swaps, trackers, etc.), certain insurance products (types 21, 23, and 26), crypto-assets, and currencies.
Pension-related insurance schemes and employer group insurances remain exempt.
The law introduces three categories: internal gains (i.e. sales to companies controlled by the seller or their family), significant shareholdings, and all other types of financial asset disposals not covered under the previous two categories.
Gifts, inheritances, marriage settlements, and in-kind capital contributions are excluded as they do not qualify as a ‘transfer for consideration’.
How Capital Gains Are Calculated
Capital gains are the difference between the sale price and the acquisition cost, without deductions for fees or taxes. Losses may be offset against gains in the same category within the same year.
For financial assets acquired before January 1, 2026, any capital loss will be calculated as the negative difference between the transfer price (whether in cash, securities, or any other form) and the value as of December 31, 2025 (‘snapshot date’), rather than the original purchase price.
There is, however, an exception: for transfers occurring up to December 31, 2030, the taxpayer may request that the capital gain be calculated based on the positive difference between the transfer price and the original acquisition cost of the financial asset, as evidenced by the taxpayer. This makes it possible to offset historical capital losses for a period of five years following the entry into force of the new capital gains tax.
For identical assets, the FIFO (first-in, first-out) principle will be used.
Stock Options & Incentive Plans
For shares or equivalent instruments acquired through the exercise of stock options that were already taxed at the time of grant (under the Law of 26 March 1999), the acquisition value is determined based on the value of the shares or instruments at the moment the option is exercised. As a result, a disposal that takes place immediately after exercise should, in principle, not give rise to a taxable capital gain (under normal private asset management).
Tax Rates & Exemptions
The standard tax rate is 10%. There is an annual exemption of €10,000 (indexed annually) with a carry-forward of up to €1,000 per year for five years (maximum €15,000).
For significant shareholdings, there is a €1 million exemption followed by a tiered rate: 1.25% up to €2.5 million, 2.5% up to €5 million, 5% up to €10 million, and 10% above €10 million.
An exemption for the first €1 million would function like a kind of ‘backpack’—a tax-free buffer that can be used once every five years. The available balance would decrease each year by the amount of capital gains that had already been exempted under this rule in the preceding four years. The rate for the first bracket (1.25%) would then apply to the extent that the €1 million exemption is no longer available.
Withholding Tax & Reporting
The new tax comes on top of the 0.15% Securities Accounts Tax and the 0.45% Patrimony Tax for Legal Entities.
A 10% withholding tax will by Belgian banks and intermediaries will only apply to two of the four categories of financial assets—namely, financial instruments and certain insurance contracts. For crypto-assets and currencies, no withholding obligation applies, meaning that in these cases, the taxpayer is responsible for reporting and paying the tax themselves.
In addition, an opt-out mechanism is provided, allowing taxpayers to avoid being subject to advance payment through withholding tax. This option also helps prevent Belgian banks from being placed at a competitive disadvantage compared to foreign intermediaries who are not required to withhold tax. The opt-out must be selected per (securities) account, and all account holders must jointly agree to it. If even one account holder does not consent, the withholding tax will continue to apply to all holders of that account.
Finally, the withholding tax will be final and discharging, although in certain cases it may still be useful or necessary to file a tax return—similar to how investment income is currently sometimes declared in personal income tax filings.
Historical Gains & Valuations
The new tax applies to capital gains from 1 January 2026 onwards. Historical gains remain exempt, while historical losses cannot be deducted. This implies that the value of financial assets will need to be properly determined as of 31 December 2025 (‘snapshot date’).
To determine these values, the government offers a broad option list. For any listed financial assets, the closing price on 31 December 2025 will serve as the definitive and irrevocable valuation.
For unlisted financial assets, however, one of three valuation methods can be used—with the taxpayer required to apply the method that results in the highest value:
- 1. Market-based valuation: the value used in a transfer for consideration of the same financial assets between independent parties, or in the context of the company’s incorporation or recent capital increase, between 1 January and 31 December 2025.
- 2. Contractual valuation: the value established by a valuation formula set out in a contract or a contractual put option regarding the financial assets, provided the contract is in effect on 1 January 2026.
- 3. Equity-based valuation: for shares or equivalent instruments, the value may also be determined by the company’s own equity, increased by an amount equal to four times the EBITDA of the last financial year ending before 1 January 2026.
Finally, taxpayers may choose to deviate from this last method by obtaining an independent valuation by a statutory auditor or an ‘independent’ certified accountant, and must be completed by 31 December 2026 at the latest.
Parallel Taxes Remain Unchanged
The existing concept of ‘normal management of private wealth’ remains fully intact, contrary to what was proposed in the original draft texts. As a result, debates over whether a transaction falls within the scope of normal management will persist. If a transaction is deemed to fall outside this scope—i.e. qualifies as abnormal management—the familiar 33% tax rate applies instead of the new capital gains tax.
Other existing taxes, such as the 30% Reynders Tax and the 16.5% tax on non-EEA share sales, remain in place as well.
What This Means for Taxpayers
This reform marks a historic change in Belgian tax law, effectively introducing a general capital gains tax for financial assets. However, rather than simplifying the system, the reform coexists with existing rules, exemptions, and reporting obligations, making expert guidance more crucial than ever.
We will carefully examine and analyze the further technical aspects of the new tax as soon as they become available in the months to come.