Indexing rent in Brussels: rules, calculation and common mistakes

Indexation lets you adjust the rent each year to the cost of living. In Brussels it is neither automatic nor unrestricted: it follows precise conditions, and a mistake can force you to repay amounts collected over several years.

Two preconditions

Since October 2022, a Brussels landlord may only index the rent if the lease is registered and a valid EPB certificate has been given to the tenant. If either condition is missing, the indexation request is invalid. An EPB certificate that expires during the lease must be renewed before any further indexation.

When and how to index

Only a written lease can be indexed. Indexation is possible once a year, from the anniversary of the lease's entry into force. It must be requested in writing. Backdating is limited to the three months before the request.

The formula

For a home rated EPB A to D:

The base rent is the rent agreed at signature, excluding charges. The starting index is that of the month before the lease was concluded. The new index is that of the month before the anniversary date. Statbel publishes the indices and an official calculator.

Homes rated E, F or G

For certain leases concluded before 14 October 2022 on homes rated E, F or G, a correction factor applies to the result. It depends on the EPB rating and the lease's anniversary date. Brussels Housing publishes the factors in force.

Most common mistakes

• Starting from the last indexed rent instead of the base rent.
• Indexing an unregistered lease, or without an EPB certificate given to the tenant.
• Forgetting to index for several years, then claiming arrears beyond three months.
• Including charges in the indexed rent.

What BDW Invest does

For every managed property, we track the anniversary date, check registration and the EPB certificate, calculate the indexation and send it to the tenant in due form.

Sources: Bruxelles-J, rent and indexation · Brussels Housing, correction factors · Statbel, rent calculator