Rent indexation in Wallonia: everything you need to know
In Wallonia, residential rent indexation is governed by the decree of 15 March 2018 and by the federal Law of 6 August 1993. The EPC capping window ended on 31 October 2023, but the EPC D to G leases it affected have since followed a special calculation method.
In short: in Wallonia, indexation is annual, on the anniversary of the lease's effective start date. It applies to all registered residential leases. Since 1 November 2023, EPC D to G leases indexed during the 2022-2023 capping window follow a special method; the others follow the federal standard formula.
The rules of rent indexation in Wallonia
The Walloon decree of 15 March 2018
The decree of 15 March 2018 on residential leases (integrated into the Walloon Housing Code, art. 27 et seq.) is the main regional framework for residential leases in Wallonia. It complements the federal indexation mechanism set out in the Law of 6 August 1993 and details the landlord's obligations throughout the lease (inventory, deposit, indexation, notice).
For the indexation calculation formula itself, the Walloon decree invents nothing: it aligns with the federal standard formula. Its regional specificity lies in the decree of 19 October 2022: an EPC-based capping window (2022-2023), followed by a permanent special calculation method for the EPC D to G leases concerned (see below).
Conditions to be met
Indexation is a right for the landlord, but subject to several cumulative conditions:
- Registered lease with the competent registration office within 2 months of signature. Without registration, indexation is not due — the tenant can legitimately refuse.
- Written request to the tenant (simple letter or registered mail). An indexation applied without written notification is invalid.
- Anniversary date of the lease's effective start respected — neither earlier nor later.
- Once a year only, with no possible accumulation with other revisions.
Periodicity (annual only)
Indexation is calculated each year on the anniversary of the effective start date of the lease (and not on the signature date, unless both coincide). If you forget to request indexation for several years, retroactivity is strictly limited to 3 months by the law: beyond that, you permanently lose the right to the unclaimed amounts.
The role of the EPC since 2022
Between 2022 and October 2023, Wallonia had introduced — like Brussels and Flanders — a mechanism to cap indexation for energy-inefficient properties, as part of anti-inflation measures. Concretely, the worse the property's EPC rating (E, F, G), the less indexation could be applied.
Historical table of Walloon EPC coefficients
D-G leases with an anniversary in the 11/2022-10/2023 window: indexation computed from the window's adapted rent (decree of 19/10/2022). Other leases: 100%.
These coefficients no longer apply as such for indexations after 31 October 2023. To retroactively check an indexation between 2022 and October 2023, the calculator applies them automatically based on the requested indexation date.
Since 1 November 2023: a special method for EPC D to G leases
Since 1 November 2023, Walloon rents can be indexed again — but not all in the same way. For leases whose property is rated EPC D, E, F or G and which had an anniversary during the capping window, the decree of 19 October 2022 imposes a permanent special calculation method: the calculation is rebased on the adapted (capped) rent of that period, with the health index of the month preceding that anniversary as starting index. Classes A to C and more recent leases follow the federal standard formula. Details on our EPC Wallonia page.
How to find your EPC?
The EPC certificate has been mandatory in Wallonia for rental properties since 2010. To find it:
- Check your lease (the EPC must be annexed)
- Contact the certified assessor who issued it (10-year validity)
- Request a copy from the notary if the property was purchased with EPC
- Have a new EPC issued (count €200-300 depending on the property size)
How to calculate your indexation in Wallonia
Our Wallonia calculator automatically applies the federal formula, the historical EPC coefficient for indexations in the 2022-2023 window, as well as the special method for the EPC D to G leases concerned.
Worked example (Walloon lease signed on 1 June 2021, rent €800, EPC C, indexation on 1 June 2026):
Health index May 2021: 110.99 — Health index May 2026 (estimated): 132.47
Indexed rent = 800 × (132.47 ÷ 110.99) = €954.83
Pitfalls to avoid
- Confusing the signature date with the effective start date of the lease (indexation is calculated on the latter)
- Using the smoothed health index instead of the raw one (the smoothed is for wages, not rents)
- Claiming more than 3 months of retroactivity (legally impossible)
- Indexing an unregistered lease (legally void)
- Forgetting to send the written notification to the tenant
What to do if the tenant refuses the indexation?
A Walloon tenant can refuse an indexation for several legitimate reasons: unregistered lease, indexation beyond 3 months retroactive, miscalculation, or simply not having received the notification letter. Before any judicial dispute:
- Verify your calculation with our calculator — an error on your side is more frequent than one might think.
- Re-notify by registered mail with acknowledgment of receipt, motivating it and attaching the calculation detail (our notification PDF is designed for this).
- If blocked, refer to the justice of the peace of the property's commune. The procedure is free and the decision comes within a few weeks.
Indexation of Walloon rents in 2026
Statbel's health index evolves monthly. In 2026, the index hovers around 132 (base 2013 = 100), in moderate increase compared to 2025. Indexations have accumulated since 2021 about +20 % increase for leases having weathered the entire 2022-2024 inflationary period.
To track the evolution month by month and anticipate upcoming indexations, see our health index table updated daily from Statbel.
Frequently asked questions — Wallonia
When can a rent be indexed in Wallonia? + −
Once a year, on the anniversary of the lease's effective start date. The lease must be registered and the indexation must be notified to the tenant in writing.
Does the EPC still apply in Wallonia? + −
Yes, for one category of leases. The capping window ended on 31 October 2023, but leases rated EPC D to G that had an anniversary between November 2022 and October 2023 have since followed a permanent special calculation method: the calculation is rebased on the adapted (capped) rent of that period. Classes A to C and more recent leases follow the federal standard formula.
Which index should I use? + −
The raw health index published monthly by Statbel. This is the index that excludes volatile products (alcohol, tobacco, fuel) — it is NOT the smoothed health index used for wages.
What if the tenant refuses the indexation? + −
First send a motivated registered letter. If the disagreement persists, the justice of the peace decides free of charge upon simple petition.
My Walloon lease dates from 2019: can I index retroactively? + −
Not beyond the last 3 months. Retroactivity is strictly limited by the Law of 6 August 1993. Beyond that, the unclaimed indexation is permanently lost.
My lease is not registered: am I entitled to index? + −
No. Registration is a precondition. Without registration, indexation is not due and the tenant can legitimately refuse it.
Is registered mail required for the indexation notice? + −
Not legally mandatory — a simple letter is sufficient. But we strongly recommend it to keep proof of dispatch in case of dispute.
Does the Walloon decree of 2018 apply to my commercial lease? + −
No. The 2018 decree only covers residential leases. Commercial leases follow the federal Law of 30 April 1951 and their indexation is regulated differently (often through a contractual clause).
Going further
- Wallonia calculator
- Methodology of our calculation
- Health index table
- Comparison with Brussels
- Comparison with Flanders
Page updated on 4/5/2026. Sources: Walloon decree of 15 March 2018, Walloon decree of 19 October 2022 (Wallex), Law of 6 August 1993, Royal Decree of 24 December 1993, Statbel. This content is informative and does not constitute legal advice. For any disputed situation, consult a lawyer or the justice of the peace.