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The landlord wants to raise the rent unfairly

Your landlord wants to increase the rent unfairly in Belgium. Indexation rules, prohibited mid-lease increases and tenant's remedies.

EH Par Edouard Hennin 3 min de lecture Mis a jour le May 28, 2026
Sommaire · 4 sections Reduire ▴

Rent increase rules in Belgium

Rent in Belgium is strictly regulated. The landlord cannot freely increase the rent during the lease.

SituationIncrease possibleLimit
During the leaseAnnual indexation onlyHealth index
At triennial deadlineRevision by agreement or judgeMarket value
Between tenantsFreeIndicative grid (Brussels)
After works (between tenants)FreeProportional to the added value
EPC E-G lease (Brussels)No indexationBlocked since 2022

In Fatima’s case, the landlord announces +15% without legal grounds. This is illegal during the lease. Only annual indexation (approximately 2-3%) is permitted.

Refuse in writing

If the landlord announces an illegal increase, refuse in writing and continue to pay the normal rent (indexed if applicable). Do not give in to pressure. The landlord cannot evict you for having refused an illegal increase.

The mechanism

Indexation is an automatic adjustment of the rent based on the health index (consumer price index excluding tobacco, alcohol, fuels). It is permitted once per year, on the anniversary date of the lease.

Formula

Indexed rent = base rent x new health index / health index of the month of signing

Example for Fatima

  • Base rent (2022): 750 EUR
  • Health index at signing: 110
  • Current health index: 118
  • Indexed rent: 750 x 118 / 110 = 804.55 EUR

The legal increase is 54.55 EUR (7.3% over 4 years), not 110 EUR (15%) as the landlord demands.

EPC block

In Brussels, properties with EPC E, F or G cannot be indexed since October 2022. Fatima should check the EPC score of her apartment.

For the indexation calculation, see our guide on rent and charges.

Recognising an abusive increase

Illegal situations

SituationLegal?
15% increase without groundsNo
Indexation exceeding the health indexNo
Increase for “works carried out” during the leaseNo (unless written agreement)
Increase for “market rise” during the leaseNo
Eviction threat if increase refusedNo (blackmail)
Indexation on an EPC E-G property in BrusselsNo (blocked)
SituationLegal?
Annual indexation according to the health indexYes
Revision at the triennial deadline (by agreement or judge)Yes
Increase between tenantsYes
Increase agreed by written amendmentYes

Your recourse as a tenant

Step 1: Refuse in writing

Send a registered letter to the landlord:

  • Reminder of the indexation rules (applicable law)
  • Calculation of the legal indexed rent
  • Refusal of the requested increase
  • Commitment to pay the legal rent (indexed if applicable)

Step 2: Continue to pay the normal rent

Pay the legal rent (indexed if applicable), not the amount demanded by the landlord. Keep payment evidence.

Step 3: Refer to the justice of the peace

If the landlord insists, threatens or refuses payments:

  • File a conciliation application (free)
  • If conciliation fails, refer to the justice of the peace
  • The judge will set the legal rent and can order the landlord to pay damages
  • Municipal mediation service (free)
  • Bar legal aid (if modest income)
  • Tenant associations (SNPC on the landlord side; no official tenant union in Belgium but associations exist)

Request reimbursement of overpayment

If you have already paid the illegal increase, you can claim reimbursement of the overpayment before the justice of the peace. The limitation period is 5 years.

To check the legal amount of your rent, use our online lease generator which calculates indexation automatically. For other cases, see our case studies.

Verifie & redige par
Edouard Hennin
Real estate expert since 2018, Edouard supports Belgian landlords and tenants through their rental processes. He oversees the writing of every guide in collaboration with the legal team and ensures all content reflects current legislation in Brussels, Wallonia and Flanders.
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Publie May 19, 2026
Derniere verification May 28, 2026
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