Indexation

Indexation adjusts certain amounts every year to follow prices. In Belgian real estate, it mainly applies to the cadastral income and to rents. The cadastral income is multiplied by a coefficient set every year by FPS Finance: 2.3 for 2026. This indexed cadastral income is the basis for property tax. For a main residence lease, the rent can be indexed once a year, on the anniversary of the date the lease took effect, based on the health index. In all three regions, indexation is allowed unless the lease expressly rules it out, provided the lease is in writing and the landlord asks for it in writing. It cannot go back more than three months before the request. In Wallonia and Brussels, the lease must also be registered, and in Brussels the landlord must have given the tenant the EPB certificate. The new rent cannot exceed the base rent multiplied by the new index and divided by the starting index.