Child Maintenance in Belgium: Calculation, Extraordinary Expenses and Review

Few issues after a separation are as sensitive as child maintenance (onderhoudsbijdrage / contribution alimentaire), often called “child support” in everyday language. How much does a parent have to pay, how is it calculated, what about school costs or a brace, and what happens if circumstances change? The law starts from a clear principle, but applying it requires precision. This article explains how child maintenance in Belgium is set, how it is adjusted and what you can do if it is not paid.

The principle: each parent contributes in proportion to their means

Parents must, in proportion to their means, provide for the housing, maintenance, health, supervision, education, training and personal development of their children (Article 203(1) of the old Civil Code, oud Burgerlijk Wetboek / ancien Code civil). This duty rests on both parents, whether they were married, living together or never a couple at all.

Means include not only earned income, but also income from movable and immovable property and all benefits and other resources that determine the standard of living of the parents and the children, such as a company car or rent-free housing (Article 203(2)). A parent who earns less still contributes according to their ability.

The obligation does not end automatically at eighteen. As long as the child’s education or training has not been completed, it continues after the age of majority.

How is child maintenance in Belgium calculated?

There is no statutory calculation formula. The law does, however, set out the elements the judge must state in the decision (Article 1321 of the Judicial Code), including:

• the income and resources of each parent;
• the children’s residence arrangements;
• the child’s ordinary costs and how they were estimated;
• family allowances (the Groeipakket in Flanders) and the tax benefits relating to the children.

In practice, lawyers and judges use calculation methods, such as the Renard method or the method of the Gezinsbond (a Flemish family association), to reach an objective estimate. These methods offer guidance, but the judge is not bound by them. Because the decision must state these elements, parents can check how the amount was arrived at.

The child’s costs are divided between the parents in proportion to their means, taking into account the costs each parent bears while the children are staying with them. With equally shared residence and comparable incomes, the contribution may therefore be small, or even limited to sharing the extraordinary expenses.

Ordinary and extraordinary expenses

The law distinguishes ordinary expenses, which cover the child’s day-to-day life, from extraordinary expenses (buitengewone kosten / frais extraordinaires): exceptional, necessary or unforeseeable costs that arise from accidental or unusual circumstances and exceed the usual budget (Article 203bis of the old Civil Code). Think of major medical costs, a brace, special school costs or study costs.

A royal decree of 22 April 2019 lists the extraordinary expenses and provides that, except in cases of urgency or proven necessity, they require prior consultation and the agreement of both parents, covering both the expense itself and its amount. The parent who wishes to incur such an expense must therefore first ask the other parent for their agreement. The royal decree does not set a time limit within which the other parent must reply; such a time limit can, however, be laid down in the judgment or the agreement. So make the request in writing and in a way you can prove, for example by registered post.

A good arrangement also sets out in what proportion the extraordinary expenses are shared and how often accounts are settled. Always check first what your judgment or agreement says on this point.

Indexation

Child maintenance is adjusted by operation of law to changes in the consumer price index (Article 203quater of the old Civil Code). The paying parent must therefore apply the indexation themselves; anyone who forgets builds up arrears. The judgment or agreement usually states the base index and when the adjustment takes place.

Review when circumstances change

If a parent loses their job, the residence arrangements change or a child moves into student accommodation, the contribution can be reviewed. The court may increase, reduce or cancel the contribution when new circumstances significantly change the situation of the parents or the child. Do not wait too long to request an adjustment: until there is a new decision, the old contribution remains payable.

An agreement between the parents can also be formalised, either in an agreement approved (homologated) by the family court (familierechtbank / tribunal de la famille) or in a notarial deed. The agreement then has the same enforceability as a judgment. A merely private agreement is not an enforceable title: if it is not complied with, you must first go to court. In a divorce by mutual consent, the arrangement for the children forms part of the agreements approved by the court.

What if child maintenance is not paid?

If payment does not arrive, several remedies are available, and you can also combine them:

• Direct payment authorisation (ontvangstmachtiging / délégation de sommes): the judge can authorise the parent to whom maintenance is owed to collect the other parent’s wages or other income directly from the employer or another third party (Article 203ter of the old Civil Code).
• Attachment: with an enforceable title, a bailiff (gerechtsdeurwaarder / huissier de justice) can levy an attachment. For maintenance debts, the usual limits on the attachment of wages and benefits do not apply (Article 1412 of the Judicial Code). More about attachment.
• DAVO/SECAL: the Maintenance Claims Service of the Federal Public Service Finance can, under certain conditions, pay advances and recover the arrears from the other parent. An enforceable judgment or deed is required for this. In addition, the other parent must have failed to pay, in whole or in part, at least two instalments, whether or not consecutive, in the twelve months preceding the application.
• Criminal proceedings: anyone who wilfully fails for more than two months to pay maintenance that they have been ordered to pay by a court decision no longer open to opposition or appeal commits family abandonment (familieverlating / abandon de famille; Article 676 of the Criminal Code, for offences committed from 1 September 2026: level 1 penalty).

Which documents do you need?

A contribution is only as convincing as the figures behind it. Gather the recent payslips and tax assessment notices of both parents and, for self-employed parents, the accounting records. Add proof of other income and benefits, of housing costs and of the child’s costs: school, childcare, leisure, clothing and medical expenses. The better documented the file, the less room there is for argument and the sooner an agreement or decision follows.

Frequently asked questions

Until what age is child maintenance payable?

Not automatically until eighteen, but for as long as the child’s education or training is incomplete. In certain cases, an adult child can claim the contribution themselves. Parents can agree that, from the age of majority, the contribution will be paid directly to the child.

Does my new partner’s income count?

Not directly: your new partner has no maintenance obligation towards your children. Living together may, however, reduce your own costs and thus affect your available means.

Do I still have to pay with a week-on, week-off arrangement?

That depends on the difference in income and on who bears which costs, such as school bills or clothing, and on who receives the family allowances. A contribution is therefore by no means ruled out.

Which court decides on child maintenance?

The family court. If the matter is urgent, you can also request urgent and interim measures, for example during divorce proceedings.

What if the other parent conceals their income?

The judge looks at all means and at the actual standard of living, not only at declared income. The judge can order a parent to produce documents and may draw conclusions from a refusal.

Novex Advocaten can help

We calculate a realistic child maintenance amount, draft a sound arrangement for extraordinary expenses and conduct proceedings to set, review or recover maintenance. See also our articles on residence arrangements and co-parenting and on maintenance between former spouses.

Call 0484 99 22 72 or email asfour@novexadvocaten.be.