News — Taxation & separation

Property tax:

sharing the tax reduction for dependent children after a separation

In shared custody, the reduction for dependent children can be divided between the two parents — in Brussels, Wallonia and Flanders. But never automatically, and according to three different mechanisms.

The property tax is a regional annual tax that affects the property, and not the person. When at least two children are residing in the home on 1st January, a reduction is granted. After a separation, this reduction practically benefits only the parent with whom the children are residing UNLESS the parents expressly request its sharing.

1. The principle: a reduction linked to residency

The reduction for dependent children assumes that at least two children entitled to family allowances are residing in the property on 1st January of the tax year. The legal basis is found in Article 257 of the Income Tax Code, regionalised since the sixth state reform.

Brussels: 10% of the tax per child (art. 257 §4 CIR).

Wallonia: 125 € indexed per child (art. 257, 3° CIR).

Flanders: a fixed amount per child varying according to the municipalities, proportional sharing possible since the 2023 tax year.

2. Brussels: a sharing in proportion to the time of residence

The tax form "Property Tax" published by Brussels Taxation for the 2026 tax year is explicit: " a proportional sharing of the reduction is however possible in cases of shared parental authority ". Specifically, equal housing entitles each parent to 5% per child; an 80/20 housing arrangement gives 8% and 2%.

The application must be submitted by 31 March at the latest of the tax year, accompanied by a certificate from the family allowance fund and a document establishing the distribution of housing: judgment, approved agreement, certified mediation agreement, or a certificate signed by both parents.

Example. Two children, equal housing, tax of €1,500. Without application: €300 savings for the resident parent, €0 for the other. With application: €150 for each. Over ten years, €1,500 changes hands.

3. Wallonia and Flanders: two different logics

The SPW Finance states that in cases of joint parental authority and equal housing, the reductions are shared equally between separated or divorced parents. The sharing is therefore flat (50/50) and not proportional. If one of the parents does not live in the Walloon Region, half of the reduction is still granted to them.

In the Flemish Region, the Flemish Tax Administration has allowed since the 2023 tax year a proportional distribution between co-parents, provided that both reside in Flanders.

4. The trap of split residency

Domiciling a child with each parent seems fair but is a false good idea. From a tax perspective, it is the worst configuration: the threshold of two children is not reached anywhere, no reductions are granted, neither to one nor the other. The choice of domicile must therefore be arbitrated with full knowledge of the facts, and then compensated in the agreement.

5. Deadlines, claims and forgotten reductions

• 31 March : deadline for the sharing request in Brussels, every year.
• 193 days : claim period if the reduction does not appear on the tax notice. First pay the total amount: the administration will then reimburse.
• BE HOME Grant (€160 in 2025, Brussels): granted to the owner residing in the property.
• Disability : additional reduction of 20% per household member recognised as disabled, applicable from the first child.
• Tenants : the reduction also exists but only the owner can apply for it; it is then deducted from the rent.

6. Our recommendation: include it in the agreement

The divorce agreement or parental agreement must explicitly mention the percentage of time spent with each parent : without this figure, the administration has no distribution key. We systematically add the mutual commitment of the parents to submit the request on time and to pass on the necessary documents.

At the Divorce House, this question is addressed in the financial and tax aspect of support, alongside the legal and human aspects — because a few well-written lines are worth, here, several hundred euros per year.

This document is not a legal consultation. For any questions regarding your personal situation, do not hesitate to contact us.

Our multidisciplinary team is at your disposal to assist you.

Sources

• Brussels Taxation, Tax sheet — Property tax, tax year 2026 (admin.be.brussels).
• Income tax code 1992, article 257 (Brussels, Walloon and Flemish regional versions).
• Constitutional Court, ruling no. 23/2018 of 22 February 2018 (shared custody and tax benefits).
• SPW Finance — FAQ "shared custody and property tax reductions".
• Flemish Tax Authority — proportional distribution between co-parents (from the 2023 tax year).
• Families League, "Brussels: property tax reductions for families" (01.12.2025).
• Webinar "Families & taxes" June 2026, Mr. Jean-Emmanuel Beernaert (Delahaye Lawyers / ULB) for the Families League.