Four out of five objections to a new or amended cadastral income (CI) result in the proposed value being wholly or partially reduced, according to data from Belgium’s Ministry of Finance.
Between 2020 and 2025, 65% of resolved objections led to a lowered cadastral income. In 15% of cases, the objection was fully upheld. On average, the income fell by 25%, with a median decrease of 14%.
Despite this, few property owners challenge the assessed cadastral income. Over that same period, an annual average of 4,220 objections were filed. The cadastral income directly affects property tax: a higher CI means higher annual real estate taxes.
Cadastral income is a notional rental value, indexed annually. Its calculation is typically based on building plans, permits, and other documents assessed by surveyors from the administration for measurements and valuations within the Ministry of Finance.
