Belgium has long been a tax haven for investors. Unlike many European countries, we didn't have to pay taxes on the profits we made from selling stocks or ETFs.
But that's about to change. The new Belgian government plans to introduce a 10% capital gains tax on financial assets in 2026.
Before you panic: there's a yearly exemption of €10,000, and the tax only applies to future gains. Here's what you need to know about the new tax and how it affects your investments, particular for ETF investors.
What is the capital gains tax?
In January 2025, the new Belgian government reached an agreement. As part of the coalition agreement, it will introduce a capital gains tax of 10% on all types of financial assets:
- ETFs (and index funds, ETNs, ETCs)
- Stocks
- Bonds
- Currencies and commodities like gold
- Crypto assets
- Financial derivatives like options
They named the new tax a "solidarity contribution". Up until now, Belgium did not have a capital gains tax on stocks and equity ETFs.
When will they introduce it?
The tax will be introduced on January 1, 2026. But the tax first needs to be formalised into law, which will likely happen during the summer of 2025. We will then also know the full details.
How is the tax calculated?
Difference between sale and buy price
Capital gains will be calculated as the gross difference between the sale price and the purchase price, excluding any transaction fees and taxes.
If you’ve made multiple purchases or sales of the same investment, specific rules will apply to determine the (fictional) order in which your shares are sold. This will likely follow the First-in, First-out (FIFO) principle. This means the oldest shares will be sold first.
Snapshot on 31 December 2025
For everything you already own before that date, the “tax purchase price” will be set to the market value on 31 December 2025. Historical capital gains are exempt.
But to avoid cases where you’d still be at a loss and yet owe tax, there’s a five-year transition period (2026 to 2030). During this time, if the actual price you paid for an asset is higher than its value on 31 December 2025, you can still use your original purchase price instead. You must be able to prove it though.
You can offset gains with losses
So if you made a €10,000 profit on the sale of a stock, but a €20,000 loss on the sale of another, the result is a net loss so you won't be taxed. However, you won't be able to carry losses forward to future years.
€10,000 exemption that can go up to €15,000
Fortunately, the government will provide an exemption of €10,000 per year. This amount will be adjusted every year for inflation.
And the exemption can grow to €15,000. If you don't use the exemption in a given year, you can carry along €1,000 of the exemption to the following year, with a maximum of €15,000. In other words, if you don't use the exemption for 5 years, you can claim an exemption of €15,000.
However, you will have to claim the exemption through your annual tax declaration. So it can take for up to 2 years for the government to actually pay you back.
Pension saving is exempt
Both pension saving (pillar 3) and complementary pension (pillar 2) are exempt. Pension saving has its limitations compared to ETFs, but at least the government won't tax it more than it already does.
The Reynders tax remains
There was a special capital gains tax that only applied to accumulating bond ETFs, the Reynders tax. It unfortunately continues to exist, even after the introduction of the new capital gains tax. But accumulating bond ETFs aren't taxed twice, only by the Reynders tax.
But this does mean that the new tax on capital gains will now also tax distributing bond ETFs, albeit with a reduced 10% tax rate.
How to declare and pay the tax
It's expected that Belgian brokers will automatically withhold the capital gains tax for you, like they do for the other taxes. However, it's unclear how they will handle the €10,000 yearly exemption.
Brokers will play a key role. If your broker is based in Belgium, they’ll likely withhold the capital gains tax at the source every time you sell an investment. At the end of the year, these brokers will provide a tax statement you can use to fill in your personal tax return. If too much tax was withheld, you’ll be able to claim it back.
If you’re using a broker that doesn’t operate in Belgium, don’t expect much help with the new tax. They probably won’t withhold anything for you or send you a tax form. So you’ll be on your own to calculate and report everything correctly. It’s a hassle, and mistakes are easy to make.
Strategy for Belgian ETF investors
A tax on capital gains is naturally negative for ETF investors. Here's what to keep in mind when dealing with the new situation.
Don't change your core strategy
Tax optimisation matters. But it’s just as important to stay focused on the core philosophy and strategy behind your investment plan. The new tax may be a change, but it’s not expected to seriously affect the key principles of a solid, long-term investing approach.
Sell slowly when reaching your financial goal
When you reach your financial goal, it will be smart to slowly sell parts of your investments each year rather than sell everything in one go. This way, you can make use of the yearly €10,000 exemption.
Trade one ETF for another
Unfortunately, the tax incentivises more frequent selling to take advantage of the €10,000 exemption. We expect that wash sales will not count towards the exemption. A wash sale is when you sell an asset in order to buy it again straight away.
But instead, you can sell an ETF and buy an equivalent one. For instance, you sell iShares' MSCI World ETF and replace it with Amundi's. Cause even though they are technically different securities, the underlying assets are very similar. You'll have to weigh it against additional broker fees and the TOB.
It's unknown yet at this point if this will be allowed.
Time your losses
If you were planning on selling an asset at a loss, make sure you time it well so you can offset it with a gain.
Be careful not to trade too much
If you’re investing speculatively, you could face a much higher tax rate: 33% on your capital gains. This applies to what the tax authorities consider short-term speculation, including:
- Frequent trading, like day trading or swing trading
- Using leverage, meaning investing with borrowed money
- Betting on volatility, through complex products like options, futures, or turbo certificates
Whether you fall into this category will depend on your behaviour and transaction history. The tax office will make that call based on how you invest.
Mixed ETFs remain uninteresting
The Reynders tax remains. This means that the capital gains for mixed accumulating ETFs will be taxed twice: the bond portion at 30% and the stock part at 10%. But it remains unclear how it will be calculated in practice as we can see it become incredibly complicated. After all, due to the movements of the markets, the ratio between bonds and stocks within a fund will be in constant fluctuation.
The final details still need to come
All these tactics are tentative. Over the next few weeks, as details appear, the best strategy to follow will become clearer.
The tax punishes long-term investing
At one point, there was talk to remove the capital gains tax if you held an ETF or stock for longer than 10 years. Unfortunately, this exemption was scrapped. It's disappointing because the tax now punishes long-term investing. When you hold assets for several decades, you're likely to make large gains. The tax means that frequent trading is rewarded instead. This goes against what's best for you as an investor.
We struggle to understand the government's reasoning. The state pension is already under huge pressure, and it keeps growing. In 2023, 20% of Belgium's entire budget went to the state pension. Every year that number increases. If more Belgians saved for their own pension through long-term investing, it would ease some of that pressure. Instead, the capital gains tax puts you off doing exactly that.
Our conclusion
The capital gains tax coming to Belgium in 2026 changes the game for investors, but it's not as scary as it first seems. With a 10% rate and a €10,000 yearly exemption that can grow to €15,000, many small investors won't feel a huge impact. The key is understanding that only gains from 2026 onwards count, and you can offset losses against gains.
What matters most is staying the course with your long-term investment strategy. Yes, there will be new tax considerations to navigate, but don't let that stop you from building wealth through investing. If you're worried about handling these complexities yourself, remember that Curvo takes care of the technical side so you can focus on what really matters: growing your money over time.
The information presented here is up-to-date at the time of writing. But it changes frequently so it might be outdated when you read this. Check at the top when this article was last updated, and please remember to do your own research!