Capital gains tax

Capital gains tax is a 10% tax on the gain made from 1 January 2026 when selling financial products such as shares, bonds, funds, and savings-linked and investment-type insurance.

The law is currently pending passage through Parliament, but will apply from 1 January 2026. This means that any capital gains you make from that date on will fall under the new tax, even if the law is not officially passed until later.

What does that mean for you?

• Capital gains realised before 1 January 2026 remain exempt
• Capital gains realised on or after 1 January 2026 will be taxed at 10% regardless of when the law is passed.

The tax applies to:

• Natural persons who are subject to personal income tax in Belgium.
• Certain legal entities subject to the tax on legal entities (mainly non-profit organisations, foundations and private foundations). However, the Bill provides an exception for non-profit organisations that are eligible to receive tax-deductible donations.

Only Belgian residents are subject to this tax.

Example
You reside permanently in France and file your tax return there. You hold your investments in Belgium. When selling certain shares, you realise a capital gain. You will not be liable to pay capital gains tax.

The tax does not apply to capital gains realised by a company.

It covers many different types of financial products such as shares, bonds, funds, options, trackers, ETFs, warrants, capital redemption insurance, investment-type insurance, gold, foreign exchange, etc. It also includes crypto-assets. It covers both Belgian and foreign products, both listed and unlisted. For unlisted products, a valuation must be carried out in the manner provided by law.

Capital gains tax does not apply to:

• Group insurance and other contracts within the second pension pillar
• Pension savings plans
• Long-term saving

Balanced bank funds are funds that consist of an equity portion (shares) and a bond portion. At present, these funds are already subject to a kind of 'capital gains tax' known as the Reynders tax. This tax will be deducted and will continue to apply alongside capital gains tax. Thus, when selling an investment fund subject to this tax, you are liable to two taxes:

• 30% withholding tax on the return on the bond portion
• 10% capital gains tax on the return of the share portion

Capital gains

A capital gain is the difference between the price paid for an asset and the price for which it is later sold. As the new law only takes effect from 1 January 2026, only capital gains accrued on or after that date will be affected. Historical capital gains are therefore not subject to the tax. To determine the gain, we look at the value of the product on 31 December 2025 (the ‘snapshot value').

Example
You bought a share in 2023 at a price of 100 euros, and sell it on 15 September 2026 for 150 euros. Over the entire period, you therefore realise a capital gain of 50 euros. However, the price of the share on 31 December 2025 is 120 euros. As a result, you pay only 10% of 30 euros (150 - 120) in tax.

Capital losses

It is perfectly possible that in addition to capital gains in a given year, you may also realise capital losses. You can deduct these capital losses from the capital gains you made in the same year, across different types of investments.

Example
In 2027, you realise a total capital gain of 25 000 euros by selling various investments. You also sell some investments in the same year on which you realise a loss of 3 000 euros. The net taxable capital gain is then 25 000 - 3 000 = 22 000 euros (leaving aside any exemptions).

Historically higher acquisition value

If you bought a share before 31 December 2025 at a higher price than the ‘snapshot value’, you will be allowed to use the higher purchase price instead of the snapshot value. It is not yet clear what supporting documents you will need to provide for this. This option only applies until 31 December 2030; For transactions after that date, the snapshot value on 31 December 2025 will be used.
However, using a historically higher acquisition value can never result in realising a minus value. It will, however, ensure that the capital gain on which tax is due is reduced to 0 euros.

Example
You bought a share in 2023 for a price of 150 euros. The price on 31 December 2025 ('snapshot value') is 120 euros. You sell the share on 15 September 2026 for 125 euros. So you would have to pay 10% on a gain of 5 euros (the difference between the selling price and the snapshot value on 31 December 2025). However, you didn’t realise a real capital gain as you bought the share for more than you sold it for. Until 31 December 2030, you can apply the historical purchase price that you actually paid.

Each taxpayer has an annual exemption. No capital gains tax is payable on the first 10 000 euros of capital gains realised. This amount is indexed annually. You need to claim this exemption on your personal tax return.

Example
You sell investments in 2026 and realise a total capital gain of 11 000 euros. If you claim the exemption on your tax return, you will only have to pay capital gains tax on 1 000 euros.

In addition, you can carry forward a limited proportion of the exemption you don’t use to the following year. For each year that you don’t make use of this exemption, you can carry forward up to 1 000 euros to a subsequent year, up to a maximum of five years. This makes it possible for each taxpayer to claim a maximum exemption of 15 000. A married couple could therefore end up with a joint basic exemption of 30 000 if they carry forward the full exemption amount (assuming their investments form part of their joint assets).

Example
You do not sell any investments in 2026. You can claim an exemption of 11 000 euros in 2027. If you sell investments which realise a total capital gain of 10 600 euros in 2027, you will not have to pay any capital gains tax in the year 2027.

The law on capital gains tax will not yet have been passed at the start of 2026. You can read below the various ways you can choose to pay the tax.

1. How do you pay the tax?

Once the law enters into force, you have two options:

• Option 1: Declare everything yourself (opt-out)
  • You opt for KBC not to deduct any capital gains tax
  • We report your choice to the tax authorities and provide you and the tax authorities with a statement detailing your realised capital gains
  • You are personally responsible for declaring these amounts in your tax return

How do you make this choice?
From the end of January 2026, you can easily arrange this in KBC Mobile, KBC Touch or in your KBC branch. You will receive additional information in this regard at that time.

• Option 2: Automatic deduction (withholding tax)
  • If you don’t opt out, KBC will automatically deduct 10% capital gains tax when you realise a gain on selling an investment
  • We will transfer that amount anonymously to the tax authorities
  • If you decide to use the exemption, you can claim back the amount paid on your tax return (we'll provide you with a statement for this purpose)

How do you make this choice?
You don't have to do anything for this option.

Example
You sell shares in June 2026 and realise a capital gain of 9 000 euros. Your financial institution will deduct capital gains tax of 900 euros on this transaction and will itself forward the money (anonymously) to the tax authorities. Since you can make use of the exemption of 10 000 euros, you can declare this capital gain on your tax return for your income year 2026/assessment year 2027 in order to recover the tax paid of 900 euros.

Tax cannot be deducted at source for certain financial products (such as capital gains on crypto-assets, foreign currency and gold). For these products, you are responsible for declaring any capital gains on your own personal income tax return.

For securities that you hold outside Belgium, you will also have to declare any realised capital gains on your personal income tax return.

For non-profit organisation and foundations, the system of deducting the tax at source does not apply; instead, payment of the capital gains tax is arranged directly through the legal entities withholding tax return.  

If you are co-holder of a joint account
Every account-holder has to make the same choice (declare everything yourself or opt for automatic deduction).

2. How do you pay before the law enters into force?

The tax applies as from 1 January 2026, but the law will not be published until later.

• If you decide to opt out and therefore don’t have the tax deducted automatically, it is your responsibility to declare all the capital gains realised in 2026 in your tax return.
• If you’ve opted for the tax to be deducted automatically, KBC will start KBCwithholding it as soon as the law enters into force.
  During the transition period, the law is expected to provide the possibility of having the 10% capital gains tax paid through your bank. We’ll inform you about this as soon as more details become available.

Where a shareholder has a substantial interest in a company whose shares they sell, the capital gains tax rules will differ from the standard regime. This deviating rule aims to treat 'owners' of (family) businesses (which were often founded by themselves or by relatives from a previous generation) less harshly and is designed not to frustrate the entrepreneurial spirit of these 'shareholder-entrepreneurs'.

For the purpose of this rule, a 'substantial interest' is defined as a participating interest of at least 20%. Only the shareholding held by the shareholder themselves and in their personal name is taken into account. Earlier rumours that shares held by family members or held indirectly (e.g. through a management company) might also be taken into account when determining the 20% minimum threshold are therefore no longer an issue. Moreover, the assessment of the 20% holding size condition takes place at the time of the transaction itself. It is therefore not enough that you have held a 20% stake at some point in the (recent) past; only the situation at the time of sale is relevant. There is no ‘transitional regime’ for shareholders who do not reach the minimum threshold of 20%, but only own, say, 19% of a company's shares; they will therefore fall under the 'standard regime' of 10% tax and a 10 000 euro basic exemption.

Shareholders who do meet the condition will benefit from an exemption on a first tranche of 1 000 000 euros when realising a capital gain. Higher capital gains will be taxed at a progressive rate (1.25% up to 2 500 000 euros; 2.5% up to 5 000 000 euros; 5% up to 10 000 000 euros; 10% for 10 000 000 euros and above). The exemption is expected to apply once per five-year period.

The deviating regime applies to capital gains on shares of both listed and unlisted companies. For unlisted companies, the question naturally arises as to the 'initial value' of the shares (the 'snapshot value’ on 31 December 2025). A number of options are given for determining this value. If a transaction took place in 2025 (e.g. a sale of shares), the value used in that transaction can be used as the reference value (‘snapshot value’). In other cases, a standardised valuation method (four times EBITDA plus shareholders' equity) can be used. You may also have a detailed valuation carried out by an auditor or certified accountant. Taxpayers are expected to be able to choose the method that yields the highest valuation. However, the taxman has the option to dispute the value.

For the sake of clarity, the scheme is not limited to shares of operating companies. It therefore also applies in principle to capital gains realised on the sale of shares of, for example, a family holding company, a management company or a holding company.

Ultimately, the introduction of a capital gains tax on financial assets does not change the basic principle that the transactions in question should still fit within the normal management of a private asset. 'Normal management' is traditionally defined as 'acts performed by a prudent and reasonable person for the purpose of day-to-day management, but also with a view to the profitability, realisation and reinvestment of elements of his assets'.

If transactions do not fall within this framework of ‘normal management’ (and are therefore classed as 'abnormal management'), realised capital gains will be deemed to be ‘miscellaneous income’ and subject to a tax rate of 33% (+ supplementary local tax). The question of whether or not a transaction falls within the definition of ‘normal management’ is obviously a question of fact, on which only a court can provide a definitive ruling.

Case law uses various criteria to judge whether the realisation of a capital gain forms part of the ‘normal management’ of a private asset. One of the transactions considered here involves 'speculation'. Some cryptocurrency holders, for example, who had hoped that the introduction of a 10% ‘solidarity contribution’ (capital gains tax) would exempt them from the potential application of a tax rate of 33% (+ supplementary local tax) on their capital gains, will thus potentially miss out. 
Another familiar example of potentially 'abnormal management' concerns 'internal capital gains'. In such transactions, a shareholder/natural person realises a capital gain on selling their shares to another company (holding company) incorporated or controlled (directly or indirectly) by the seller. The tax authorities (and the finance minister) considered that such a situation did not constitute ‘normal management’. However, given that the judgement regarding ‘normal management’ can only be made by a court with jurisdiction over the substance of the matter, the case law is more ambiguous on this point.

The regime in relation to ‘internal capital gains’ is now being tightened up and embedded in legislation. When a shareholder sells shares to a company in which that shareholder exercises control (alone or in conjunction with family members), a separate levy of 33% will apply to the capital gain.

Capital gains realised when contributing shares to a holding company will however still be tax-exempt. In fact, a specific regime already applies for the contribution of shares, whereby the capital for tax purposes of the company which receives the contribution is limited to the acquisition cost of the contributed shares. From a tax perspective, the net contribution is deemed to be a 'taxed reserve', which is subject to 30% withholding tax upon subsequent distribution.