Paying capital gains tax in 2026: what are your options and what are the implications?

Once the law enters into force, you have 2 options:

• You opt for KBC Brussels not to withhold any capital gains tax
• We report your choice to the tax authorities and provide you and the tax authorities with a statement detailing your realised capital gains
• You are personally responsible for declaring these amounts in your tax return
  

You can easily arrange this in KBC Brussels Mobile, KBC Brussels Touch or at your KBC Brussels branch from the end of January 2026 on. You will receive additional information in this regard at that time.

• If you don’t opt out, KBC Brussels will automatically deduct capital gains tax at a rate of 10% when you sell an investment at a profit
• We will transfer that amount anonymously to the tax authorities
• If you decide to use the exemption, you can claim back the amount paid on your tax return (we'll provide you with a statement for this purpose)

You don't have to do anything for this option.

If so, all the holders have to make the same choice (declare everything yourself or automatic deduction).

The tax applies as from 1 January 2026, but the law will not be published until later.

• If you decide to opt out and therefore don’t have the tax deducted automatically, it is your responsibility to declare all the capital gains realised in 2026 in your tax return.
• If you’ve opted for the tax to be deducted automatically, KBC Brussels will start withholding it as soon as the law enters into force.
  The government is working on a solution regarding payment of the capital gains tax you owe during the transition period.

Learn more about capital gains tax.