The tax applies to natural persons as well as legal entities (such as companies, non-profit organisations and foundations), founders of legal arrangements, partnerships and entities with joint ownership of property, and to both Belgian and foreign residents.

• Belgian residents are subject to the tax in respect of both custody accounts held with Belgian intermediaries (such as banks) and custody accounts held with foreign intermediaries
• Foreign residents are only subject to the tax in respect of custody accounts held with Belgian intermediaries

An exception applies for foreign residents who are able to claim relief under a double taxation treaty in which the authority to levy taxes on assets has been assigned to their country of residence.

Certain companies are excluded for custody accounts held exclusively for their own account. These are  ‘financial entities’ such as banks, listed companies, asset managers, funds and insurers.

The tax applies to all financial instruments held in a custody account, including turbos and trackers.

The tax does not apply to investment-type insurance products. However, the intention is to tax custody accounts held by insurance companies for unit-linked life insurance products. This is because the legislator argues that these custody accounts are not held ‘for own account’.

Only custody accounts with an average value of more than 1 million euros fall within the scope of the tax. The number of holders of the custody account holders has no impact. This means that the average value is not divided by the number of account holders. For example, a custody account with a value of 1.2 million euros and three account holders will be subject to the tax.

To calculate the average value, ‘snapshots’ of the account will be taken every three months. This takes place on 31 December, 31 March, 30 June and 30 September.

If the average value exceeds 1 million euros, a rate of 0.15% is applied. An exception is made for custody accounts with a maximum value of 1 015 228.43 euros. For these accounts, the tax is set at a maximum of 10% of the difference between the taxable basis and 1 million euros.

In principle, the reference period runs from 1 October in a given year to 30 September in the following year. In some cases, the reference period will end early. This may be the case, for example, when a custody account is closed. Another example is when the sole holder of the custody account relocates to a country with which Belgium has signed a double taxation treaty in which the authority to levy taxes on assets has been assigned to the holder's country of residence.

Example 1
Els is the holder of a custody account. On the reference dates, the following values are calculated:

• 31 December 2025: 2.2 million euros
• 31 March 2026: 2.3 million euros
• 30 June 2026: 1.7 million euros
• 30 September 2026: 1.9 million euros

The average value is: (2.2 + 2.3 + 1.7 + 1.9)/ 4 = 2.025 million euros

Under the new law, if the value is more than 1 million euros, a rate of 0.15% is applied to the average value of the custody account. In our example, therefore, tax of 3 037.50 euros is payable.

Suppose in our example Els had closed her custody account on 5 July 2026; there are then only three reference dates:

• 31 December 2025: 2.2 million euros
• 31 March 2026: 2.3 million euros
• 30 June 2026: 1.7 million euros

The average value is: (2.2 + 2.3 + 1.7/ 3 = 2 066 667 euros. In that case, the amount of tax payable is 3 100 euros. In our example, the tax is due on 6 July 2026 (the day after the closure of the custody account).

Example 2
A custody account with a value of 1 001 000 euros is subject to a tax of 100.00 euros rather than 1 501.50 euros.

For custody accounts held with Belgian intermediaries (such as banks), the intermediary will calculate and deduct the tax.

If the tax is not deducted, the account holder must file a return themselves and pay the tax to the tax administration.

A statement was published in the Belgian Official Gazette on 4 November 2020 announcing the introduction of the tax on custody accounts. The statement also made reference to the general anti-abuse provision that is being introduced.

This provision stipulates that certain acts carried out by a taxpayer with a view to avoiding the tax are subject to rebuttable presumption and non-enforceable against the tax authorities. The taxpayer must then provide counter-evidence in order to avoid this anti-abuse provision.

The statement provides a number of examples:

• The splitting of custody accounts
• The transferring of securities from one custody account to another
• The conversion of certain securities into registered securities

The Explanatory Memorandum to the new Act provides further examples of acts which the legislator will assume are intended solely for the purpose of evading the tax. If the tax authorities invoke this anti-abuse provision, the taxpayer can attempt to rebut the presumption.

The Minister has confirmed that it is not up to the financial intermediary to judge the intentions of its customers. The intermediary must however inform the customer of this anti-abuse provision and the fact that the tax authorities are not obliged to accept certain acts.

The anti-abuse provision came into effect with retroactive force on 30 October 2020.

In addition to a general anti-abuse provision, two specific situations (specific anti-abuse provisions) were recently introduced under the annual tax on custody accounts legislation. Those situations are also presumed to be non-enforceable against the tax administration.

The new ‘Arizona’ coalition government believes that the tax administration was able to exert too little control over acts carried out by holders of a custody account with the aim of evading tax. Therefore, the Programme Act of July 2025 contains two new specific anti-abuse provisions.

These concern acts deemed to be non-enforceable against to the tax administration because they are presumed to have been carried out purely to evade the annual tax on custody accounts. The taxpayer does have the opportunity to show that there are other, valid motives for carrying out these acts that do not represent an abuse.

They include the following areas:

• The conversion of securities into registered form that are held in a custody account and whose value exceeds 1 million euros.
• The transfer of some of the securities that are held on a custody account and whose value exceeds 1 million euros, to one or more other custody accounts held solely or jointly by the same customer.

To enable monitoring of this measure, the bank where the custody account is held must report these transactions to the tax authorities. The tax authorities can then ask questions of the account holder to ascertain the motives behind the action in question.

If the holder of the custody account is able to demonstrate that the transfer was carried out for by motives other than the avoidance of the tax, there is no further consequence for the calculation of the annual tax on custody accounts. If the holder fails to demonstrate this, the value of the registered or transferred securities must be taken into account in determining the 1 million euro threshold and calculating the tax due. In that case, it is up to the holder of the custody account to file an additional annual tax on custody accounts return and pay the tax due.

As regards accounts held abroad, the holder must personally notify the tax authorities.

Jan has a custody account ‘A’ containing various securities. The value on 2 May 2026 is 1.6 million euros. On 3 May 2026, he decides to transfer 800 000 euros’ worth of securities to a new custody account ‘B’, which he opened in his own name. He opened this account with his bank.

To calculate the annual tax on custody accounts, the average value of the custody account is looked at on 30 September. In this example, the average value of custody account A is 950 000 euros. Since the value has not reached the threshold of 1 million euros, his bank will not deduct JTER from custody account A. The average value of custody account B amounts to 800 000 euros on 30 September 2026. Again, the bank will not deduct JTER.

Due to the new anti-abuse provision, however, his bank will notify the tax authorities of this transfer of 800 000 euros and they can question John about it.
If John cannot demonstrate that this transfer was prompted by reasons other than avoiding the annual tax, he will have to make an additional declaration and pay the tax as if this transfer had not taken place. Suppose the average value of custody account A was 1.75 million euros on 30 September 2026 if the transfer had not taken place, John would have to pay 2 625 euros in tax.

Some examples of valid reasons

• A gift to the holder’s children where a portion of the securities is transferred to another account for which the children are joint holders with the donor, This can be done, for example, when creating a partnership that allows the donor to retain control of the gifted securities.
• The transfer of securities from a custody account in the event of divorce.

Example of a non-valid reason
According to the Explanatory Memorandum to the Law, transferring securities to another custody account in the context of splitting short-term and long-term investments would not be a valid motive.