Property tax evolution in Belgium: 50 years without cadastral revision

History of the cadastral income

The cadastral income (revenu cadastral / kadastraal inkomen) is the basis for calculating property tax in Belgium. It represents the fictitious annual net rental income a property could have generated on 1 January 1975.

Since that date, the cadastral income has never been subject to a comprehensive revision (equalisation). It is simply indexed annually by a coefficient (1.9084 in 2026). Property tax is calculated on this indexed cadastral income.

This situation is unique in Europe. France, the Netherlands and Germany periodically revise their cadastral values. In Belgium, a property purchased for EUR 50,000 in 1975 and worth EUR 350,000 today still has a cadastral income reflecting the 1975 value.

The gap between cadastral income and reality

The Court of Audit published in 2025 a report estimating the gap between the cadastral income and real values:

In concrete terms, a Brussels apartment with a cadastral income of EUR 800 (1975 basis) should have a cadastral income of EUR 2,000-2,500 if a revision were to take place. The annual property tax could rise from EUR 1,400 to EUR 3,500-4,400.

For property investors, this undervaluation is a de facto tax advantage.

The political debate: why it is stalled

In March 2026, a proposal for a progressive cadastral revision was rejected in the federal Parliament (67 against, 55 for). The arguments:

In favour of revision:

• Tax fairness: older properties in gentrified neighbourhoods pay little property tax
• Additional revenue for municipalities
• Data update (the Belgian cadastre is one of the least reliable in Europe)

Against revision:

• Massive increase for millions of property owners
• Risk of rent increases (passing on property tax)
• Technical complexity (valuation of 5 million properties)
• Estimated cost of the revision: EUR 400 million

Declaration obligation after works

Even without a comprehensive revision, property owners have the obligation to declare to the cadastre any modification that increases the comfort or floor area of the property:

• Adding a room, a bathroom, a covered terrace
• Installing central heating, a fitted kitchen
• Converting an attic or cellar into a habitable room
• Building an extension

The declaration must be made within 30 days to the cadastral office (FPS Finance). In practice, the Court of Audit estimates that less than 20% of owners comply. Penalties are rare but theoretically possible (administrative fine).

The taxation of rental income is directly linked to the declared cadastral income.

Alternatives to a comprehensive revision

Several alternatives are under discussion to modernise the system without a full revision:

1. Revision upon transaction: automatically update the cadastral income at each sale (based on the sale price)
2. Revision by zone: revise by neighbourhood in areas where prices have evolved the most
3. Replacement with a property tax: abandon the cadastral income and tax based on the updated market value (Dutch model)
4. Status quo with corrections: maintain the cadastral income but increase additional centimes in undervalued municipalities

Flanders, which has competence over additional centimes, is studying option 2 (revision by zone) for 2028-2030.

What to do as a landlord

In the absence of a revision, property tax remains predictable and relatively low:

1. Do not declare works that do not increase comfort (refreshing, painting, like-for-like replacement)
2. Declare significant conversions to avoid retroactive adjustments
3. Factor in current property tax in your yield calculation — it is an advantage as long as the cadastral income is not revised
4. Favour older properties in high-growth areas: the gap between cadastral income and real value is a tax advantage
5. Follow the debate: if a revision is voted, the impact will be massive in certain municipalities

To compare the impact of property tax by region, consult our Flanders vs Wallonia vs Brussels analysis.