The Walloon indexation rules, the role of the EPB certificate since 2023 and the correct procedure, explained for landlords.
Residential tenancy in Wallonia is governed by the decree of 15 March 2018 on residential leases. It sets the rules on duration, rental guarantee, notice and indexation. The indexation formula is the same as in the other Regions: base rent x new health index / initial index, with the initial index being that of the month preceding the signing of the lease.
Between November 2022 and 31 October 2023 Wallonia limited indexation for energy-inefficient homes. That restriction ended definitively on 1 November 2023 and, unlike in Flanders and Brussels, it was not replaced by a permanent correction factor. Since then every Walloon lease is indexed at 100 per cent of the federal formula, whatever the energy class of the property.
The absence of a limitation does not mean the absence of an obligation. A valid EPB certificate is still required for any letting in Wallonia, and its details must appear in the advertisement as well as in the lease. The label no longer determines the amount of the indexation, but its absence can lead to administrative penalties and complicate any dispute before the justice of the peace.
In Wallonia, registering the lease with the Federal Public Service Finance is compulsory and is the landlord's responsibility. The formality is free. It has a direct consequence: the increase resulting from indexation is only due if the lease has been registered. A landlord who neglected this formality therefore risks having an indexation request successfully challenged, even where the calculation is perfectly correct.
The Walloon indexation rules, the role of the EPB certificate since 2023 and the correct procedure, explained for landlords.
Indexation is never automatic. The landlord must request it in writing from the tenant, once a year, on the anniversary of the date the lease took effect. That request has retroactive effect for a maximum of three months from the date it is sent. Indexation forgotten for two years therefore cannot be fully recovered: beyond three months the difference is permanently lost.
Commercial leases fall under the federal Commercial Tenancy Act rather than the Walloon decree. The indexation formula is identical, the initial index always corresponds to the month before signing, and no energy considerations apply. A shop in Namur, Liege or Charleroi is therefore indexed under the same rules as one in Flanders or Brussels.
Take a lease signed in March 2021 in Liege with a base rent of 750 euro. The health index for February 2021 was 110.39; for February 2026 it was 138.06. The calculation gives 750 x 138.06 / 110.39 = 937.99 euro. After five correctly applied indexations the rent has therefore risen by 188 euro per month. A landlord who indexed only once in those five years would today receive several thousand euro less per year.
Our platform applies the correct Walloon rules: initial index for the month before signing, no EPB correction factor, indexation on the anniversary of entry into force. You enter the lease once; each year we calculate the new rent and send the indexation letter to your tenant, with you in copy. You no longer have to track deadlines or index publications.
Enter your base rent, start date and region and see straight away what you may charge this year. Based on the official health index, with the Flemish EPC correction applied automatically.
Go to the free calculator →Submit your contract and never miss an indexation.