Capital gains tax: what it means for Belgian ETF investors

July 7, 2025
4 minutes

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 ETF investments.

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, including ETFs but also stocks, bonds, crypto assets, and financial derivatives like options. They name the new tax a "solidarity contribution". Previously, Belgium did not have a capital gains tax on stocks and equity ETFs.

When will they introduce it

It's expected 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?

Only capital gains accrued from the day before the tax is introduced, so December 31, 2025, will be counted. So if you invested in an ETF 10 years ago, only the recent price matters for calculating the capital gains tax. Historical capital gains are exempt.

There's also a helpful rule for capital gains: if you bought your ETF in the past for more than its value on 31 December 2025, you can use the higher historical purchase price for up to five years back (if you can prove it).

You can deduce losses. So if you made a €10,000 profit on the sale of one ETF, 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.

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.

We don't expect foreign brokers will help you with the declaration and payment of the capital gains tax.

We're keeping a close eye on the developments of the tax, and we will ensure to minimise its impact for Curvo members.

Strategy for Belgian ETF investors

A tax on capital gains is naturally negative for ETF investors. However, it affects all types of financial assets, so it will also affect those who invest in individual stocks and crypto assets.

But there are a few ways you can reduce your tax bill.

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.

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.

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 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!