How property tax is calculated
Property tax is calculated in three steps: CI x indexation coefficient x regional base rate x (1 + additional surcharges). The CI is set by the cadastral authority, the indexation coefficient is published annually by the FPS Finance, and the surcharges depend on the province and municipality.
The detailed formula involves multiplying the cadastral income by the annual indexation coefficient (2.1763 for 2026), then applying the regional base rate and adding the provincial and municipal surcharges (expressed in centimes additionnels).
Worked example
Property with CI of EUR 1,200 located in Ixelles (Brussels).
| Component | Value |
|---|---|
| Cadastral income | EUR 1,200 |
| Indexation coefficient 2026 | 2.1763 |
| Indexed CI | EUR 2,612 |
| Base rate (Brussels) | 1.25% = EUR 32.64 |
| Municipal surcharges (3,100 centimes) | EUR 1,012 |
| Total property tax | approx. EUR 1,045 |
The same CI in a Walloon municipality with higher surcharges could result in a property tax 50 to 100% higher. The municipality is the decisive factor.
The indexation coefficient
The cadastral income dates from 1975 and has never been reassessed. Each year, the FPS Finance publishes an indexation coefficient to update it. For 2026, the coefficient is 2.1763. This indexed CI serves as the tax base for both property tax and personal income tax on rental properties.
The indexation coefficient applies to all properties uniformly. It does not reflect the actual rental value of your property. Two properties with the same CI pay the same base tax, regardless of their actual market rent.
You can find the CI of any property on your purchase deed, on the property tax notice (avertissement-extrait de role), or by requesting it from the FPS Finance cadastral office.
Rates by region
Brussels-Capital Region
Base rate of 1.25%. No province and therefore no provincial surcharges. The 19 municipalities set their own municipal surcharges (2,500 to 3,400 centimes). Property tax is managed by Bruxelles Fiscalite.
Walloon Region
Base rate of 1.25%. The 5 provinces set surcharges from 1,100 to 2,600 centimes. Municipal surcharges range from 1,800 to 3,500. The SPW Fiscalite has managed collection since 2020.
Flemish Region
Base rate of 3.97%. Provincial surcharges range from 500 to 1,430 centimes. Municipal surcharges are lower (900 to 2,000). VLABEL manages property tax in Flanders.
Articles 249 to 260 CIR 92 and regional legislation — Texts on Justel