If you are a natural person, you can choose:
1) Automatic withholding at source (default option).
2) Personal tax return (opt-out)
In practice
ING automatically withholds the tax at source and pays it to the tax authorities.
You are not obliged to declare the realized capital gains in your tax return.
Do you want to take advantage of the exemption of 10,000 euros and/or deduct any capital losses? You can do this through your tax return. You can rely on the annual overview that we will send you or on the account statements of the executed transactions.
What does the ‘automatic withholding at source’ involve?
The system combines simplicity with fiscal anonymity, since the capital gains for which the tax has been withheld do not need to be declared again.
Good to know
If you want to deduct capital losses or benefit from the exemption, you must include the capital losses and capital gains in your tax return.
Capital gains realized through foreign institutions are never automatically taxed. In this case too, you must declare them correctly in your tax return.
In practice
You can activate the opt-out via Home'Bank or the ING Banking app. Make sure you are using the latest version of the app, available on the App Store (iOS) or Google Play (Android).
You are obliged to declare the realized capital gains in your tax return.
ING must inform the tax authorities about the transactions for which the tax has not been withheld (= reporting obligation).
At the beginning of the next fiscal year, ING will provide you with an overview of the capital gains and the capital losses.
This annual overview will help you to fill in your tax return correctly.
If there are multiple account holders, all account holders need to activate the opt-out so that the tax is not deducted from the capital gains realized on the account.
What does the opt-out mean?
With the opt-out, you avoid paying a tax in advance that you might not owe. For example, if the taxpayer can benefit from the tax exemption of 10,000 euros in his tax return or deduct realized losses.
Points of attention
However, this choice requires strict monitoring: all transactions must be recorded, supporting documents must be kept, and the tax rules must be well understood, because any error or omission in the declaration can have tax consequences.
If this choice involves multiple investment accounts with different financial institutions, the follow-up becomes particularly complex without the help of a financial advisor.
ING is required by law to provide the Belgian tax authorities with information on sales transactions of financial instruments held in an investment account for which the opt-out has been activated (= reporting obligation).
This requirement for detailed reporting results in a loss of anonymity, because the tax authorities will have a full view of the capital gains realized.
ING reports to the tax authorities the total amount of capital gains realised on the account over the entire year, for all persons who are or have been account holders during that year. This also applies if they were no longer account holders at the time of certain transactions. Each client remains individually responsible for correctly reporting, in their tax return, the share of the capital gain that relates to them.
If there are multiple account holders, the detailed declaration will cover all account holders.
Capital gains realized from 1 January 2026 will be taxable.
However, ING will not be able to automatically withhold the tax on capital gains nor carry out any tax reporting (opt-out) before the new law comes into effect.
What does this mean for you?
1) You have chosen the default option with automatic withholding
2) You have chosen the opt-out
You can activate the opt-out via Home'Bank or the ING Banking app. Make sure you are using the latest version of the app, available on the App Store (iOS) or Google Play (Android).
A straightforward flow is available from your investment account.
Important: If you have multiple investment accounts, you must indicate your choice separately for each investment account for which you want to activate the opt-out.
For example, it is perfectly possible to activate the opt-out for your ING Self Invest account and to opt for withholding at source for your ING Invest Advice account.
Don't have the ING Banking app or Home'Bank yet? Follow these steps to install it.
Need help accessing the digital flow?
Our colleagues in the branch will be happy to help you at the digital devices in the customer area.
You can activate the opt-out via Home'Bank or the ING Banking app. Make sure you are using the latest version of the app, available on the App Store (iOS) or Google Play (Android).
A straightforward flow is available from your investment account
You can activate the opt-out via Home'Bank or the ING Banking app. Make sure you are using the latest version of the app, available on the App Store (iOS) or Google Play (Android).
A straightforward flow is available from your investment account
Step 1: one of the account holders follows the standard procedure.
Step 2: The other holders will receive a notification ‘Document to sign’ in the ING Banking app or in Home'Bank. All account holders must consent (= sign) within 30 days so that the opt-out is activated.
Why?
The agreement of all account holders ensures that everyone is aware of the fiscal and administrative consequences of the opt-out.
ING then provides the legally required information about each co-holder of an investment account with an opt-out to the tax authorities.
You can activate the opt‑out until the last business day of the transition period, i.e. Friday, 29 May 2026.
Your choice leads to different tax consequences depending on when you activate the opt‑out and whether or not taxable transactions (sales with capital gains or corporate actions) have occurred.
SITUATION 1
You activate the opt‑out before 29 May 2026 and you have made taxable transactions with capital gains (between 1 January and 1 June 2026).
Consequences as from 1 June 2026
Can you change your mind?
Explanation
As soon as a sale with capital gains or a securities transaction occurs during the year, the chosen option (withholding at source [LT1] or opt‑out) applies to the entire current tax year.
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SITUATION 2
You activate the opt‑out before 29 May 2026 and no taxable transaction has occurred (between 1 January and 1 June 2026).
Consequences as from 1 June 2026
Explanation
In the absence of a sale with capital gains or a corporate action, there is no concrete tax impact yet.
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SITUATION 3
You activate the opt‑out on 20 July 2026 before any sale with capital gains or securities operation.
Consequences as from the activation date
Explanation
To be fully effective for the current year, the opt‑out must be activated before any sale with capital gains or corporate action.
Validity
Once activated, this choice remains valid as long as it is not revoked by at least one of the account holders.
The revocation
New investment account
Not activating the opt‑out?
Once activated, the opt-out remains valid until it is revoked. Revocation can only take place once per tax year and will only take effect from the following year.
How can you revoke the opt-out?
Quite simply, by following the same steps as when activating the opt-out (see the section ‘How do you activate the opt-out if you are the sole holder of the investment account?’ above).
On the second screen, answer “no” to the question: ‘Do you wish to deactivate the withholding at source of the capital gains tax?’. Then confirm your choice (electronic signature).
Unlike the opt-out, the return to withholding at source does not need to be validated by all account holders. In other words, it is sufficient for one of the account holders to revoke the opt-out for withholding at source to apply to the account again from the following year.
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