Rent indexation calculator for Belgium

How it works

Rent indexation in Belgium, in short

What is rent indexation?

Most Belgian leases let the landlord adjust the rent once a year to the cost of living, on the anniversary of the date the lease entered into force. The adjustment follows the health index, a version of the consumer price index without alcohol, tobacco and motor fuels, published every month by Statbel.

How is the indexed rent calculated?

The new rent is the rent agreed at signing, multiplied by the new index and divided by the initial index. Where an energy-label correction applies, the result is also multiplied by a correction factor:

base rent × new index ÷ initial index (× correction factor)

It always starts from the rent at signing, not from last year's indexed rent, and both indexes must be taken in the same base year.

Which initial index applies?

The health index of the month before the lease was signed. In Flanders, for main residence leases signed from 1 January 2019, it is the index of the month before the lease entered into force instead.

Which new index applies?

The health index of the month before the anniversary of the entry into force. For a lease in force since 1 March, that is the index of February of the year you index for.

Is indexation automatic?

No. The landlord has to ask the tenant for it in writing, at the earliest on the anniversary. The new rent can be claimed back for at most the three months before the month of the request, so an indexation you forget for longer is partly lost.

Does the energy label matter?

Yes. When energy prices soared, the three regions limited the indexation of housing with a poor energy performance certificate (EPC, or EPB in Brussels) for a year:

• Flanders, 1 October 2022 to 30 September 2023: full indexation for labels A+ to C, half for D, none for E, F, G or without a certificate.
• Wallonia, 1 November 2022 to 31 October 2023: full for A to C, 75% for D, 50% for E, none for F, G or without a certificate.
• Brussels, 14 October 2022 to 13 October 2023: full for A to D, 50% for E, none for F, G or without a certificate.
• German-speaking Community, 1 January to 31 December 2023: full for A to D, 50% for E, none for F, G or without a certificate.

Since the freeze ended, the leases it caught keep a correction factor at every indexation, so the indexation missed that year is not simply made up afterwards. In Brussels, the rent of a main residence without an EPB certificate cannot be indexed at all.