The new Belgian Capital Gains Tax: what changes in 2026

The new Belgian capital gains tax reshapes investing, family business ownership and estate planning.

In brief

• The new Belgian capital gains tax reshapes how private investors, family businesses and families must structure their wealth.
• A valuation as of 31 December 2025 becomes central to determining future taxable gains, requiring early preparation across portfolios and family assets.
• Estate planning tools and ownership structures face new scrutiny, making proactive reviews essential to safeguard intergenerational transfers and long‑term wealth strategies.

Belgium is preparing for a profound shift in how private wealth is taxed. The new capital gains tax, expected to enter into force on June 1, 2026, fundamentally changes the landscape for individual investors, family business owners, and families engaging in estate planning. Although capital gains realized as from 1 January 2026 already fall within the new regime, the system introduces transitional valuations, distinct tax categories, operational obligations for intermediaries, and important strategic considerations for privately financial assets.

This article brings together insights from three core domains - private assets & family business, estate planning, and portfolio investments - to help taxpayers and advisers understand the new rules and anticipate their impact.
 

Scope of the new tax: who is affected and on what assets?

The tax targets Belgian tax-resident individuals and certain Belgian legal entities subject to the legal entities tax. It applies to capital gains realized outside a professional activity and within normal private wealth management, when those gains result from a transfer for consideration. Gifts, inheritances, and other transfers without consideration remain out of scope.

The law covers four major categories of financial assets:

1. Financial instruments

Shares, bonds, funds, ETFs, derivatives, options, futures, and similar instruments fall within scope. Gains are taxed upon transfer for consideration (e.g., sale). Belgian intermediaries must withhold tax unless the taxpayer opts out.

2. Certain life insurance contracts

Branches 21, 22, 23, 26 and 44 (excluding pension-based products) are included. Gains are taxed upon buy-back or surrender.

3. Crypto-assets

Defined consistently with MiCA/DAC8, crypto gains are taxable when assets are exchanged for other tokens, for fiat, or used to acquire goods/services. No withholding applies; taxpayers must report gains.

4. Currencies and investment gold

FX gains on non-payment-account currencies and gains on investment gold become taxable upon transfer. No withholding applies.
 

Tax categories: three regimes with distinct rates and logic

Not all capital gains are taxed equally. The law creates three additional mutually exclusive categories: the most specific category always applies.

1. Internal capital gains (exception regime)

This applies to sales of shares to a company controlled by the transferor - alone or together with his or her spouse, ascendents, descendants or collateral relatives  up to the second degree. Gains are taxed at a flat 33% with no exemption. This regime aims to counter transactions historically considered as abusive, such as selling shares to one’s own holding company to extract liquidity. Control may be direct or indirect, and there is no possibility of providing counter‑evidence.

2. Substantial shareholdings (special regime)

This applies when the transferor owns at least 20% of the capital or equity rights in a company whose shares are sold. Two sub‑regimes exist:

Sub-regime 1 (within EEA): Progressive rates apply depending on cumulative gains over five consecutive years:

• 1–2.5 million EUR: 1.25%
• 2.5–5 million EUR: 2.5%
• 5–10 million EUR: 5%
• Above 10 million EUR: 10%

An exemption applies for the first 1 million EUR of such gains over five years.

Sub-regime 2 (transfer to non‑EEA acquirer): A flat 16.5% rate applies.

3. General regime (residual category)

This covers all other taxable gains within normal management of the private estate. The tax rate is 10% with an annual exemption of EUR 10,000, and a limited carry-forward mechanism of up to EUR 5,000 per taxpayer (max EUR 1,000/year).
 

Valuation and taxable base: the importance of 31 December 2025

Capital gains realized from 1 January 2026 are taxable, but only gains accumulated after 31 December 2025 are taxed. The acquisition value is therefore either:

• the real historical acquisition value (if higher and evidenced, up to 31 December 2030), or
• the fair market value on 31/12/2025, based on strict rules.

For listed assets, the last closing price of 2025 is used. For unlisted assets, the law prescribes a hierarchy:

• binding valuation in a 2025 transaction,
• contractual valuation formula,
• or equity + 4× tax EBITDA.

Alternatively, a valuation by a certified accountant or auditor may be prepared before 31 December 2027.

For fungible assets, FIFO applies for historical gains, but the average price method applies for determining the “grandfathered” value at 31/12/2025.
 

Withholding tax, opt‑out rules, and the 2026 transition

A key operational feature is the withholding tax mechanism:

• For Belgian resident individuals with accounts in Belgium, intermediaries must generally withhold the tax, unless the client opts out.
• In case of  opt-out, financial institutions report gains to the tax authorities, and taxpayers declare them.
• Only via the annual tax return can taxpayers claim the deduction of capital losses, the exemption, or a higher acquisition value.
   

The transitional period (1 January–31 May 2026)

No legal basis exists for withholding the tax during this period. Taxpayers who want confidentiality may request to be withheld; otherwise, gains must be reported. From 1 June 2026, the default regime will be teh withhdoling by the Belgian intermediary  , unless an opt‑out applies.
 

Estate planning: intergenerational transfers under the new tax

The new tax deeply affects estate planning strategies.

Transfers under consideration

Sales, exchanges, company contributions, reorganizations, and certain terminations of joint ownership may trigger tax. Transfers without consideration (gifts, inheritances) remain unaffected.

Internal capital gains in estate planning

Selling shares to a children‑owned holding company does not automatically escape the regime: if the transferor still exercises control (alone or with family), the 33% internal gains rule may apply. Future actions - such as transferring the received sales proceeds to children - may also be scrutinized under anti‑abuse provisions.

Substantial shareholdings in succession situations

When share ownership is split upon death - e.g., usufruct to the surviving spouse, bare ownership to children - the 20% threshold is assessed per holder, not per family. For this purpose, shares held in bare ownership are taken into account when determining the threshold, whereas usufruct rights are not. This can lead to different taxation outcomes across family members.

Joint ownership and “uitonverdeeldheidtreding”

Ending joint ownership may constitute a taxable transfer unless specific exceptions apply (death, divorce, or termination of cohabitation) provided the division occurs within three years after the event took place.

The civil partnership ("maatschap") under scrutiny

Contributions of financial assets to a civil partnership may trigger taxable gains unless:

• the contribution relates to shares (specific exemption applies), or
• ownership proportions remain identical.

During the life of a civil partnership , transparency applies; at termination, the distribution of assets may trigger tax unless an exemption applies. Families should evaluate whether their civil partnership  structure remains future‑proof.
 

Portfolio investors: practical impacts and strategic considerations

Portfolio investors are significantly affected due to the broad scope of taxable assets, the importance of the valuation snapshot, and the administrative consequences of opting in or out of withholding.

Key operational points include:

• tracking multiple acquisition values across asset classes,
• deciding on opt‑out strategies across intermediaries,
• understanding how fungible assets are taxed,
• and coordinating reporting obligations across Belgian and foreign accounts.
   

Conclusion

The new Belgian capital gains tax represents the most significant transformation of private wealth taxation in decades. It introduces differentiated tax regimes, new valuation rules, withholding obligations, and complex implications for estate planning and family business ownership.

Taxpayers - especially those with diversified portfolios, family shareholdings, or multigenerational wealth structures - should assess the impact now, well before the law’s effective date.

In February 2026, we hosted seven webinar sessions across three key themes – Family Business & Private Assets, Estate Planning, and Portfolio Investments. These sessions brought together subject‑matter specialists to unpack the upcoming capital gains tax reform and its implications from multiple angles. You can watch or re‑watch all webinars at your convenience by simply clicking the link and registering on the platform. Access the full webinar overview here.