Cadastral Income & Review in Brussels

Cadastral Income and Review in the Brussels-Capital Region

Cadastral income (CI) is a central concept in Belgian real estate taxation. Assigned to each property by the Measurements and Valuations Administration (formerly the Cadastre Administration) of the FPS Finance, it represents the notional net rental value of the property — that is, the net income a landlord could derive from it if it were let at market conditions… as they stood in 1975. Therein lies the peculiarity of the Belgian system: the last general cadastral revaluation dates back to 1975, and CIs have since been indexed only, never globally reassessed.

Our firm assists you in verifying, optimising, and challenging your cadastral income in the Brussels-Capital Region.

The Role of Cadastral Income in Belgian Taxation

Property Tax (Précompte Immobilier)

The CI serves as the basis for calculating property tax (précompte immobilier), the Belgian land tax. In the Brussels-Capital Region, property tax is calculated as follows:

Indexed CI × Regional rate (1.25%) × Municipal coefficient (variable by commune, from 2,800 to 4,000+)

In practice, an indexed CI of 1,000 EUR with a municipal coefficient of 3,000 generates an annual property tax of approximately 300 to 500 EUR. An overvalued CI therefore entails a recurring tax surcharge, year after year.

Real Estate Income Taxation

The CI also plays a role in:

• Personal income tax (IPP) return: The indexed CI is declared as real estate income for properties that are unlet or let for private purposes. It is increased by 40% for properties let for professional use.
• Owner-occupied property relief: In the Brussels Region, the CI of a sole owner-occupied residence is exempt from property tax under certain conditions.
• Inheritance and gift duties: The CI may serve as an additional reference point (though not a determining one) in fiscal valuation.

Professional Rental Income

Where a property is let to a tenant who uses it for professional purposes, the taxable base is no longer the CI but the actual rent received. However, the CI remains relevant for calculating property tax.

When Is the CI Fixed or Revised?

• New construction: The CI is set by the administration in the months following occupation of the property.
• Works modifying comfort or surface area: Extension, raising of the roof, subdivision into flats, major renovation increasing comfort (installation of central heating, a bathroom). The owner is obliged to declare such modifications within 30 days.
• Change of use: Conversion from residential to commercial use, or vice versa.
• General revaluation: The last one dates from 1975. None has been announced to date.

Common Issues with Cadastral Income in Brussels

Overvalued CI

Certain properties are assigned a disproportionately high CI relative to their actual rental value. This is frequently the case for:

• Unrenovated townhouses (maisons de maître) whose CI was set on the basis of their theoretical potential rather than their actual condition.
• Properties that have suffered deterioration or a loss of comfort since the CI was originally set.
• Administrative errors (incorrect surface area, wrong number of rooms).

CI Not Revised Following Works

Conversely, undeclared improvement works may expose the owner to a retrospective adjustment with penalties.

CI of Subdivided Buildings

When a building is subdivided into several units (flats, studios), each unit must be assigned its own CI. Failure to apportion the CI between units creates fiscal complications.

Our Assistance

CI Verification

We analyse the consistency of your CI against the actual characteristics of your property: surface area, condition, comfort level, and location. If the CI appears overvalued, we prepare a substantiated dossier.

Challenging the CI

In the event of overvaluation, we prepare a documented technical report establishing the actual net rental value of the property (on the 1975 base, indexed). This report supports your objection to the administration within the statutory two-month deadline following notification.

Post-Works Assistance

Following works that have modified the property, we assist you in declaring the modifications and anticipating the impact on the CI, in order to avoid unwelcome surprises and to challenge an excessive revised CI.

CI Apportionment

Upon subdivision of a building, we calculate the equitable apportionment of the CI between the units, on the basis of their respective rental values.

How It Works

1. Initial contact: You describe your situation and provide the available documents (tax assessment notice, deed of sale, floor plans).
2. Analysis: Verification of the CI against the characteristics of the property and comparable CIs in the neighbourhood.
3. Report: Where a challenge is warranted, preparation of a substantiated technical report.
4. Follow-up: Assistance throughout the objection procedure with the administration.

Discover our other diagnostics and certificates, the EPC and the asbestos survey. For a valuation of the market value of your property, consult our real estate appraisal services. Contact us for an initial discussion.