Indexing alimony

Indexing alimony

Who should index the maintenance amount?

The person who is liable to pay maintenance money is also responsible for indexing this amount himself in time. The maintenance debtor is obliged to always spontaneously pay the correct amount.

Thus, it is not up to the maintenance creditor to index the alimony and communicate the new amount to the obligated party. After all, maintenance debts are not – what are called – collection debts.

When should alimony be indexed?

Maintenance payments are indexed annually and this on the due date, as determined by a court order or agreement.

For example, if payments are due from 1 December 2023, they will be indexed for the first time on 1 December 2024.

How to calculate maintenance indexation?

Both child and ex-partner maintenance payments are indexed based on the consumer price index, also known as the consumer price index.

The formula to be used to index is as follows:

new amount = (base amount x new index) / base index

Thus, to perform the calculation, the following data are necessary:

  • The basic amount:
    The basic amount is the original amount of maintenance money determined in an agreement or judgment (e.g. € 150,00 per month).
  • The basic index:
    The basic index is the index figure for the month prior to the first payment. Often the judgment or agreement explicitly states which month this refers to. (e.g. payment is due for the first time on 01 January2024, then the base index is the index for the month of December 2023).
  • The new index:
    The new index is the index figure of the month prior to the (e.g. if indexing is due on 01.01.2025, the new index is that of December 2024).

You can always find the official index figures on the website of Statbel, the Belgian statistics office.

What if no payment is made?

If payment is not made spontaneously, the amounts owed can be enforced on the basis of the judgement or agreement containing the payment obligation.

Maintenance payments and arrears indexation are time-barred after 5 years. So be sure to take the necessary action in good time.

Do you still have questions about the calculation of indexation or should you receive maintenance money and they are not paid voluntarily?

Contact us at We will be happy to help you.