Valid grounds for contesting indexation

Quick answer

Yes, a tenant can contest rent indexation when: the calculation is wrong (wrong base rent or index), the landlord did not send a written request, the property has a poor EPC label subject to restrictions, or the indexation was applied before the anniversary date.

The main grounds for contesting are:

  • Calculation error: wrong base rent, wrong health index, wrong period
  • No written request: indexation was applied without a formal notification
  • EPC non-compliance: the property’s energy label triggers indexation restrictions
  • Premature indexation: applied before the lease anniversary date
  • Lease exclusion clause: the lease explicitly excludes indexation
  • Unregistered lease: in some cases, an unregistered lease may limit indexation rights

Step-by-step procedure to contest

  1. Verify the calculation yourself using the indexation formula and official Statbel data
  2. Write to the landlord: explain the error, provide your own calculation, request correction
  3. Send by registered mail if the landlord does not respond within a reasonable time (2 weeks)
  4. Request reimbursement of any overpaid amounts
  5. Contact the Justice of the Peace (juge de paix) if the landlord refuses to correct
Practical tip

Always contest in writing with detailed calculations and references to official Statbel data. A well-documented complaint is much more likely to be resolved without court proceedings.

Evidence to gather

To support your contestation, collect:

  • Original lease: showing the base rent and signing date
  • Statbel indices: official health index for both the starting and new periods
  • Your own calculation: showing the correct indexed rent
  • Landlord’s notification: the indexation request you received
  • Payment records: showing amounts paid (especially if overpayment occurred)
  • EPC certificate: if EPC restrictions are part of the contestation

Regional specifics

Brussels-Capital Region

Under the Ordinance of 27 July 2017, tenants can contest indexation based on EPC restrictions. Properties with labels E, F or G face limitations or a complete freeze.

Wallonia

The Decree of 15 March 2018 provides similar EPC-based contestation grounds. The Justice of the Peace of the property location has jurisdiction.

Flanders

The Flemish Housing Rental Decree of 9 November 2018 provides for contestation based on EPC E and F labels. Proceedings must be in Dutch.