The new capital gains tax on financial assets

After months of negotiations, the federal government reached an agreement at the beginning of July on the main outlines of the new capital gains tax on financial assets. Although the bill is not yet final, the parliamentary discussion is expected to take place this fall. The intended effective date is set for 1 January 2026.

The article below is a summary of the most important points, with specific attention to the impact on individuals holding shares in non-listed companies. This summary is based on the texts and explanations available as of 22 July 2025.

The new capital gains tax affects both individuals subject to personal income tax and legal entities subject to corporate income tax, including non-profit organizations (vzw’s) and private foundations.

The tax will apply from 1 January 2026, when a capital gain is realized outside of professional activity and within the normal management of private assets, as a result of a transfer for consideration — in other words, when a price or compensation is received in exchange for the transfer

Do you personally hold shares in a non-listed company? Then it is important to know the following

• Applied rates and exemptions:
  • Basic rate:
    • A capital gains tax of 10% applies, with an annual exemption of €10.000 per taxpayer. This exemption is indexed and is limited in its transferability.
  • Substantial shareholding (> 20%)
    • When you hold at least 20% of the shares in a company, you are considered to have a substantial interest. In that case:
• an exemption of €1.000.000 applies (over a 5-year period). The first €10.000.000 of capital gains are taxed progressively (in tiers) at lower rates — above this amount, the basic rate of 10% applies.
  • Internal capital gains:
    • For transactions considered internal capital gains, an increased rate of 33% applies.
      
• Capital gains realized up to and including 31 December 2025 are exempt. Therefore, a “valuation date” is required to determine the value of financial assets as of that date.
  
• For non-listed shares, the value as of 31 December 2025 will be the highest of the following possible values:
  • The value based on a transaction with third parties in 2025.
  • The value based on an existing valuation formula (in a valid contract).
  • A flat-rate value (fixed formula), being the company’s equity plus four times the EBITDA of the most recently closed financial year.

In deviation from the flat-rate value, the value can also be determined by a company auditor who is not the statutory auditor, or by an independent certified accountant. Such valuations must be completed no later than 31 December 2026.

Note: The tax administration can still challenge such a valuation if it considers it not to be market-conforming (i.e., too high). No deadline is specified for possible challenges by the tax authorities. This underscores the importance of a thorough, well-supported valuation, preferably accompanied by a detailed and well-documented valuation report.

In all cases, it is advisable to carefully evaluate your current situation and, where necessary, make the appropriate preparations in time for the introduction of this new tax.

The new tax affects individuals subject to personal income tax as well as legal entities subject to corporate income tax, including non-profit organizations (vzw’s) and private foundations^[1].

The tax applies to capital gains realized from the transfer for consideration of financial assets.

Financial assets

The term "financial assets" is broadly defined and includes four categories:

• Financial instruments: listed and non-listed shares, bonds and other debt securities, certificates, money market instruments, participation rights in collective investment institutions, ETFs and ETNs, various derivative contracts (options, futures, swaps, etc.), emission allowances, and similar products;
• Certain insurance contracts: savings insurance (e.g., branches 21, 22, and 26), investment insurance (e.g., branches 23 and 44), as well as foreign contracts (e.g., branch 6 in Luxembourg);
  
• Crypto assets; and
• Currency, including investment gold.

Transfer for valuable consideration

The capital gains tax regime will only apply when a capital gain is realized outside of professional activities and within the normal management of private assets as a result of a transfer for consideration, meaning that the transferor receives compensation or a price in exchange for the transfer of their financial assets.^[2]

For the capital gains subject to this tax, there are three possibilities:

A)     Internal capital gains

B)     Capital gains related to a substantial shareholding

C)     Basic rate (for everything not covered under A or B)

The basic rate (C) is 10%, with an exemption of €10.000 per taxpayer per year. This exemption is indexed and only partially transferable if not (fully) used; a maximum of €1.000 per year can be transferred, up to a total maximum exemption of €15.000.

Capital gains classified as “internal capital gains” (A) are taxed at 33%. An internal capital gain arises from the transfer of shares (sale) by a taxpayer to a company that he or she, together with family members, directly or indirectly controls. The transfer of a family business to the next generation (e.g., the exit of the parents and takeover by children who did not yet have control) would therefore not fall under (A), but rather under (B).

(B) refers to the regime for taxpayers with a “substantial shareholding,” i.e., 20% or more. A progressive tax applies on realized capital gains, after applying an exemption on the first tranche of gains amounting to €1.000.000 over a 5-year period. The tax rates are as follows:

A special category of transfer of a substantial shareholding is a sale to a non-EEA legal entity^[3].  The tax rate for this will be 16,5%.

The capital gain is calculated as the positive difference between the acquisition value and the price received as compensation.

Costs and taxes may not be included in the calculation of the capital gain (i.e., they cannot be deducted). Capital losses may only be deducted if realized in the same year by the same taxpayer in the same category of assets.

Capital gains realized up to and including 31 December 2025 are fully exempt from tax. Therefore, it is crucial to correctly determine the value of all financial assets held before 1 January 2026, i.e. as of 31 December 2025. This value will henceforth be considered the acquisition value for the calculation of any future capital gains. This reference date is also called the “valuation date” or “snapshot.”

For many financial assets — especially listed instruments — determining this value will be relatively straightforward. For others (such as non-listed shares), a careful valuation is required.

For non-listed financial assets, the acquisition value as of 31 December 2025 is determined as the highest of the following values^[4]:

A)     A value used in a transfer for consideration of the financial assets between completely independent parties, as a result of a capital increase, or due to the incorporation of a company, that took place between 1 January and 31 December 2025.

B)     A value resulting from the application of a valuation formula set out in a contract or in a contractual offer of a sale option regarding these financial assets (for a contract valid and in effect as of 1 January 2026).

C)     In the case of shares or equivalent instruments, an amount equal to the equity plus four times the EBITDA of the last financial year ended before 1 January 2026. This is referred to as the “flat-rate valuation.”

Only as a deviation from the flat-rate valuation can the value be determined by a company auditor who is not the statutory auditor or by an independent certified accountant. This valuation must be completed no later than 31 December 2026.

The tax authorities reserve the right to review and potentially challenge the valuation determined by an accountant or auditor, even after the valuation has been completed, if there are indications that the valuation is not market-conforming—that is, if it is considered overestimated. There is no legal deadline within which such a challenge must be made. Theoretically, the tax authorities could do this many years later.

This underscores the importance of a carefully substantiated valuation, supported by a comprehensive and well-documented valuation report. Such a report should, among other things, address the company’s recent financial results, future expectations, and the market conditions prevailing as of 31 December 2025.

For shares or equivalent instruments acquired under the Share Options Act of 26 March 1999, the acquisition value is the value at the moment the option is exercised. The capital gain realized upon exercising the option is not taxable under the new capital gains tax. For example, suppose you were granted an option in 2020 with a 10-year term and an exercise price of €50. In 2030, you exercise the option. At that time, the share price is €90. The profit of €40 realized at that moment is not subject to the capital gains tax. For the calculation of any (future) capital gains tax, the acquisition value will be €90.

Additionally, there is a specific rule for shares acquired with a discount or price reduction. In this case, the acquisition value is the value of the share at the moment of acquisition (i.e., excluding the discount).

As it currently stands, the capital gains tax will be collected through withholding tax by banks and other financial intermediaries established in Belgium. However, exemptions can only be claimed through the tax return. Any capital losses will also need to be reported and offset via the tax return. Moreover, the withholding tax collection by intermediaries cannot take into account any higher acquisition value. Therefore, the application of a higher acquisition value will also have to be handled through the tax return.

It will be possible to opt to have no withholding tax withheld on capital gains (this option will apply to all financial institutions and all types of capital gains). The advantage of this is that there will no longer be any “pre-financing” in favor of the government caused by the deduction of withholding tax.

Importantly, capital gains on financial assets realized in the context of a substantial shareholding, as well as internal capital gains, will not be subject to withholding tax. These gains must be declared on the tax return.

Finally, a reporting obligation will be introduced for intermediaries involved in such transactions (substantial shareholding and internal capital gains), unless the person is bound by professional secrecy.