Short-term leases can be indexed
Yes, the rent of a short-term lease can be indexed. The same legal right to annual indexation based on the health index applies as for standard 9-year leases. In practice, for leases shorter than one year, indexation rarely occurs because the lease anniversary is not reached. For leases of 1 to 3 years, indexation is possible and follows the standard formula.
A short-term lease (bail de courte duree) is a primary residence lease, and all residential lease rules apply, including the right to annual rent indexation. The law makes no distinction between short-term and standard leases for indexation purposes.
Indexation occurs on each anniversary of the lease’s entry into force. For a 6-month lease, there is no anniversary and therefore no indexation opportunity. For a 2-year lease, the landlord can claim one indexation on the first anniversary.
When indexation applies in practice
| Lease duration | Number of indexations possible | Practical relevance |
|---|---|---|
| 6 months | 0 | No anniversary reached |
| 1 year | 0-1 | Only if renewed |
| 18 months | 1 | On the first anniversary |
| 2 years | 1 | On the first anniversary |
| 3 years | 2 | On the first and second anniversaries |
Key points:
- Indexation occurs on the anniversary of the lease entry date, not the calendar year
- The landlord must request the indexation in writing
- It is not retroactive — if not claimed on time, it is lost
- The health index of the month preceding the anniversary is used
For short-term leases under 2 years, indexation has minimal impact. However, if the lease is renewed (keeping total duration under 3 years), remember to claim indexation on each anniversary. The base rent and base index remain those from the original lease start.
Calculation example for a short-term lease
For a 2-year lease starting on 1 September 2025 with a base rent of 900 EUR/month:
- Base index: health index of August 2025 (month preceding entry)
- Indexation date: 1 September 2026 (first anniversary)
- New index: health index of August 2026
- Formula: 900 x (health index Aug 2026 / health index Aug 2025) = indexed rent
If inflation between the two periods was 3%, the new rent would be: 900 x 1.03 = 927 EUR/month.
The landlord claims this indexation in writing before or on 1 September 2026. The indexed rent applies from September 2026 for the remaining duration of the lease.
If the lease expires before the next anniversary, no further indexation occurs.
Regional specifics
Brussels-Capital Region
The ordinance of 27 July 2017 applies the same indexation rules to short-term leases as to standard leases. Brussels energy-related indexation restrictions also apply to short-term leases for poorly performing properties.
Walloon Region
The decree of 15 March 2018 makes no distinction for indexation purposes between short-term and standard leases. Walloon indexation restrictions for poorly performing properties apply equally.
Flemish Region
The Vlaams Woninghuurdecreet of 9 November 2018 treats short-term leases identically for indexation purposes. Flemish EPC-related indexation limits (E or F label) apply to short-term leases as well.
Regional housing legislation on rent indexation applies uniformly to all primary residence leases, regardless of duration. Short-term leases are not exempt from indexation rules.