Who is affected from 1 January 2026
Belgium's Programme Law, adopted in 2025 under Chamber dossier 56K1244, applies the new regime to covered capital gains on financial assets realised from 1 January 2026. It matters especially when you use a foreign broker such as Interactive Brokers, DEGIRO or Trading 212. Those brokers may give you trade statements, but they do not normally turn the records into a Belgian return.
For the ordinary category explained here, Article 171 sets a 10 percent separate rate. The separate rate is subject to favourable globalisation. If calculating tax on all your income at the ordinary scale gives a lower result, that lower treatment applies. You need your complete income picture to make that comparison.
A separate substantial-holding regime
A holding of at least 20 percent can fall under a progressive regime ranging from 1.25 to 10 percent. That regime is not covered here.
The base exemption and supplemental tranches
The annual base exemption has a statutory amount of EUR 4,855. After indexation, it is about EUR 10,000 for assessment year 2027. Apply that base exemption to the eligible annual balance after same-category loss netting.
Unused base exemption can also build supplemental tranches. Each year's statutory tranche is EUR 480, which is about EUR 1,000 indexed at the assessment year 2027 coefficient. The tranche for a year is reduced by the base exemption actually used in that prior period. Available supplemental amounts are used oldest first and are capped at EUR 5,000 indexed per year.
This does not create an automatic EUR 15,000 exemption. A supplemental tranche exists only after it has been earned in a prior period, and its amount depends on how much base exemption was used then.
Investments you already owned before 2026
For assets held before the regime began, the default basis is the value on 31 December 2025. For listed assets, use the last closing price of calendar year 2025. This separates gains that arose before the new tax from gains arising under it.
For disposals through 31 December 2030, you can elect to use documented actual acquisition cost instead. Keep the original contract notes because the election depends on evidence and may be more favourable for assets bought above their 31 December 2025 value.
Transaction fees and taxes are excluded from gains and losses. Losses can offset gains only within the same category and only for the current year. A broker's headline profit figure may therefore differ from the Belgian calculation.
What to keep from a foreign broker
Keep each buy and sell confirmation, quantities, execution dates, prices, currencies, fees and taxes. For positions acquired before 2026, also preserve the original acquisition evidence and the relevant 2025 year-end price. Foreign-currency trades need enough history to support conversion at the statutory dates.
Do not rely only on the broker's current cost basis. Account transfers, corporate actions and broker migrations can overwrite or omit the history needed to support the 31 December 2025 basis or the actual-cost election.
What AllInvestView will do
AllInvestView already tracks transaction lots, fees and foreign-exchange history across brokers. That is the evidence layer the Belgian calculation needs. The Belgian filing pack will ship when the implementing decrees and official filing guidance are final. We are not promising a date before those materials settle the remaining filing details.
Explore the tracking and reporting features, or create an account to start preserving your portfolio history now.
Frequently asked questions
Not tax advice. This is a general explanation of the enacted 2026 regime. Implementing decrees, filing guidance and your own facts can affect the result.