What changed on 1 January 2026
Until 31 December 2025, capital gains on shares, ETFs, bonds, and most other financial assets held by Belgian private investors as part of the normal management of their private estate were completely exempt from personal income tax. Belgium was one of the last EU countries without a broad capital gains tax.
The Arizona coalition agreement of June 2025 introduced the new regime. From 1 January 2026, gains on financial assets are taxed at a flat 10%, subject to a €10.000 annual exemption. Crucially, the law applies only to gains accrued from 1 January 2026 — all historical gains built up before that date remain permanently tax-free through the step-up mechanism.
You are taxed at 10% on the gain between the value of your asset on 31 December 2025 (or your purchase price if you bought after 2026) and the sale price. Everything you earned before 2026 is untouched. The law targets future growth — not your existing wealth.
The law entered into force on 1 January 2026 even though the formal parliamentary vote was still pending at that date. This unusual situation created a transitional period: Belgian brokers and intermediaries were not required to withhold the 10% tax at source until the 10th day after the law's formal adoption. KBC confirmed automatic withholding begins 1 June 2026. For gains realised between 1 January and that date, taxpayers must self-declare via their annual tax return.
What assets are covered
The new tax has a deliberately broad scope. It covers financial assets held by Belgian tax-resident individuals in the context of normal private wealth management.
| Asset type | In scope? | Note |
|---|---|---|
| Listed shares (Belgian and foreign) | ✓ Yes | 10% on gains from 2026 |
| ETFs and investment funds | ✓ Yes | Partial Reynders tax interaction — see below |
| Bonds and debt instruments | ✓ Yes | 10% on capital gain component |
| Cryptocurrency and digital assets | ✓ Yes | Must self-declare — no broker withholding |
| Foreign currencies (above normal use) | ✓ Yes | Must self-declare |
| TAK 23 / TAK 26 insurance contracts | ✓ Yes | Capital gain portion only |
| TAK 21 savings insurance (funeral / outstanding balance) | ✗ Exempt | Carved out by amendment |
| Main residence and direct real estate | ✗ Exempt | Not financial assets |
| Assets received via gift or inheritance | ✗ Exempt | Transfer itself not in scope |
| Assets already taxed as professional income | ✗ Exempt | No double taxation |
The step-up mechanism — how historic gains are protected
This is the most important aspect of the new regime for existing investors. The acquisition value used to calculate your taxable gain is not what you originally paid for the asset. Instead it is:
- Listed securities: the closing price on 31 December 2025
- Unlisted shares: the higher of several methods — equity plus 4× EBITDA from the last financial year before 2026, or a value certified by an independent auditor (deadline: 31 December 2027)
- New arrivals to Belgium from 2026: the market value on the date of arrival in Belgium
If your original purchase price was higher than the 31 December 2025 value — meaning the asset was worth less at year-end 2025 than you paid — you may use your actual acquisition cost instead of the step-up value, but only for disposals before 31 December 2030. You must declare this in your tax return. Using a higher historic cost can reduce the gain to zero but cannot create a deductible loss for CGT purposes.
The €10.000 annual exemption
The first €10.000 of net capital gains in each calendar year is exempt from the 10% tax. This amount is indexed annually. Only gains above this threshold are taxed — but you must report your gains to claim the exemption. If you do not report, you cannot claim it.
Unused portions of the exemption can be carried forward — but only up to €1.000 per year, for a maximum of five years, giving a cumulative maximum exempt amount of €15.000.
| Year | Gains realised | Exemption used | Carry-forward added | Cumulative carry-forward |
|---|---|---|---|---|
| 2026 | €3.000 | €3.000 | €1.000 (unused) | €1.000 |
| 2027 | €2.000 | €2.000 | €1.000 (unused) | €2.000 |
| 2028 | €0 | €0 | €1.000 | €3.000 |
| 2029 | €18.000 | €10.000 + €3.000 c/f = €13.000 | — | €0 |
| Tax in 2029: (€18.000 − €13.000) × 10% = €500 | ||||
CGT rates by situation type
The 10% rate applies to most private investors. But the law establishes three distinct regimes depending on the nature of the transaction and the size of your shareholding.
| Situation | Rate | Exemption |
|---|---|---|
| Standard financial assets — normal private management | 10% | €10.000 annual |
| Substantial shareholding (≥20% of a company) — gains within EEA | 0%–10% progressive | €1.000.000 base exemption |
| Substantial shareholding — sale to non-EEA company | 16,5% | — |
| Internal capital gains (sale to company you control) | 33% | None |
| Speculative transactions — abnormal private management | 33% | None |
Substantial shareholding — progressive rates
If you hold 20% or more of a company's capital (individually — family members are not aggregated), a separate progressive regime applies with a €1.000.000 base exemption.
| Gain above €1.000.000 | Rate |
|---|---|
| €0 – €1.000.000 (first tranche above base exemption) | 1,25% |
| €1.000.000 – €2.500.000 | 2,5% |
| €2.500.000 – €5.000.000 | 5% |
| Above €5.000.000 | 10% |
How the tax is collected
Belgian broker withholding (from 1 June 2026)
For most listed financial instruments and eligible insurance contracts, Belgian banks and brokers withhold the 10% tax at source automatically when you sell. This withholding is liberating — once deducted at source, you have no further obligation to declare that gain.
However, if you want to claim the €10.000 annual exemption back (because the broker withheld tax on gains that fall within your exemption), you must claim the refund via your annual personal income tax return. The broker provides a statement for this purpose.
Self-declaration required for
- Cryptocurrency and digital assets — brokers cannot withhold on these
- Foreign currencies
- Securities held at foreign brokers outside Belgium
- Substantial shareholdings and internal capital gains
- Gains realised between 1 January and 1 June 2026 (transitional period)
No Belgian intermediary withholds CGT on cryptocurrency gains. If you realised crypto gains in 2026, you are responsible for declaring them in your Belgian personal income tax return (aangifte / déclaration). The 10% rate applies to gains on all crypto assets from 1 January 2026 — using the 31 December 2025 closing value as your acquisition cost.
Capital losses
Capital losses on financial assets can be offset against capital gains in the same tax year across different asset categories. A loss on ETFs can reduce a gain on shares in the same year. However, losses cannot be carried forward to future years — this is a key difference from the UK system.
To deduct losses, you must report all capital gains in your annual tax return. If you do not declare, you lose the right to offset losses. Losses can only be offset via the tax return — Belgian brokers deducting tax at source do not account for losses you may have realised elsewhere.
Interaction with the Reynders tax
Belgium's existing Reynders tax (taxe Reynders / Reynders-taks) imposes a 30% tax on the interest component of gains realised on investment funds that hold more than 10% of their assets in debt instruments. This continues to apply alongside the new CGT.
For a mixed fund that holds both equity and bonds, part of the gain is subject to the 30% Reynders tax (the interest/bond portion), and the remaining capital gain portion falls under the new 10% CGT regime. This creates a dual regime for some fund investors that significantly increases compliance complexity. The exact split depends on the fund's composition and is typically reported by the fund itself.
If you hold mixed funds (bond + equity), the taxable portions under each regime must be calculated separately. Belgian fund administrators are required to report the applicable split. Check your fund's annual tax reporting documentation or contact your broker to confirm how the 30% Reynders component and 10% CGT component are being applied to your holdings.
Exit tax — leaving Belgium
Belgian residents who transfer their tax residence outside Belgium are subject to an exit tax on unrealised gains accrued from 1 January 2026. The exit tax applies if you dispose of the assets within two years of leaving Belgium.
An automatic deferral applies if you move to an EU or EEA member state, or to a country that has a tax treaty with Belgium including mutual assistance provisions. The deferral lasts 24 months. If you do not sell the assets within those 24 months and remain in a qualifying country, the exit tax obligation expires and no tax is due in Belgium.
For moves to non-treaty countries, deferral requires posting security or collateral with the Belgian tax authorities.
Worked example — mixed portfolio disposal in 2026
An investor holds an ETF portfolio worth €180.000 on 31 December 2025. In September 2026 they sell €50.000 of ETFs. The ETFs had risen to €56.000 at the time of sale. They also sell crypto held since 2023 — worth €8.000 on 31 Dec 2025, sold for €9.500.
Note: the ETF gain is withheld at source by the broker (from 1 June 2026). The crypto gain must be self-declared. To claim the exemption on both, the investor must file the annual return and request the broker's withholding to be refunded.