Is there a cap on rent indexation in Belgium?

Brief answer

In Belgium, no percentage cap frames the indexation of residential rents: the official formula (Rent × New index ÷ Starting index) mechanically follows the Statbel health index, regardless of its magnitude. The only limits are regional and EPC-related. In Brussels (leases that entered into force before 14/10/2022, EPC E, F or G) and in Flanders (contracts that entered into force before 1/10/2022, EPC D, E, F or no EPC), the indexed rent is multiplied by a correction factor of about 0.89 to 0.99. In Wallonia, the capping period ended on 31 October 2023, but the EPC D to G leases it affected have since been indexed under a special method that restarts from the adapted rent.

The principle: no federal cap

The indexation formula — article 1728^bis of the former Civil Code, taken over by article 26 of the Walloon decree of 15 March 2018 and by article 34 of the Flemish Residential Tenancy Decree — imposes no maximum percentage on annual indexation. It is neutral:

Indexed rent = Base rent × (Health index of the month preceding the anniversary of the entry into force ÷ Starting index)

The starting index is that of the month preceding the conclusion of the lease in Brussels and Wallonia, and of the month preceding the entry into force in Flanders (leases concluded since 2019). If the health index rises 9 % in a year (case of 2022), the rent rises 9 %. If it falls (rare but possible), the indexed rent would in theory fall — the question is debated and the case is extremely rare; consult a professional.

For the complete formula and our legal sources, see our methodology.

The real caps: regional EPC corrections

Where the formula imposes nothing, the three regions have introduced reduction mechanisms that act as a de facto cap on energetically inefficient dwellings.

Brussels: correction factor only for old leases

EPC class	Current regime	Effect on the indexed rent
A, B, C, D	100 %	Full ordinary formula
E	× factor ≈ 0.945 to 0.990	About 1 to 5.5 % lower
F, G	× factor ≈ 0.891 to 0.980	About 2 to 11 % lower

This correction factor (article 224/2, § 1/2 of the Brussels Housing Code — ordinance of 13 October 2022, then ordinance of 13 October 2023, in force on 14 October 2023) only applies to leases that entered into force before 14 October 2022. It multiplies the full result of the formula, and its value depends on the anniversary month. For leases that entered into force from 14 October 2022: indexation at 100 %, all classes. In every case, no indexation is due in Brussels if the lease is not registered or if the EPC certificate has not been provided to the tenant. Detail in our Brussels page.

Flanders: correction factor for contracts predating October 2022

EPC label	Current regime	Effect on the indexed rent
A+, A, B, C	100 %	Full ordinary formula
D	× factor ≈ 0.945 to 0.980	About 2 to 5.5 % lower
E, F or no EPC	× factor ≈ 0.891 to 0.960	About 4 to 11 % lower

The Flemish decree of 3 October 2022 (article 4) has applied these factors since 1 October 2023, with no end date, only to contracts that entered into force before 1 October 2022. More recent contracts are indexed at 100 %, whatever the label. Label G does not exist in Flanders (the scale runs from A+ to F), and an expired EPC counts as no EPC. The factor stops applying if the landlord obtains a new EPC A+, A, B or C (moving from E or F to D switches to the D factor) or in case of a new contract.

Wallonia: end of the period, but permanent special method

Wallonia experienced a capping period between 1 November 2022 and 31 October 2023 (decree of 19 October 2022, still in force). Since 1 November 2023, there is no multiplying factor, but leases rated EPC D to G or without a certificate, which entered into force before 1 November 2022 and had an anniversary during that period, are indexed under a permanent special calculation method: the calculation restarts from the adapted 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 ordinary formula at 100 %.

Official example of the Walloon administration (SPW): rent of €600, lease concluded in September 2019 and entered into force on 1 November 2019, EPC E. Adapted rent on 1 November 2022: €665.24 (instead of €703.69); on 1 November 2023: €667.22, against €705.79 with the ordinary formula.

Detail on our Wallonia page.

Recap table of caps by region and class

Current regime (September 2026)

Region	Leases concerned	Method	Order of magnitude
Brussels	Entered into force before 14/10/2022, EPC E, F or G	Result of the formula × correction factor	E ≈ 0.945-0.990 · F-G ≈ 0.891-0.980
Flanders	Entered into force before 1/10/2022, EPC D, E, F or no EPC	Result of the formula × correction factor	D ≈ 0.945-0.980 · E, F, no EPC ≈ 0.891-0.960
Wallonia	Entered into force before 1/11/2022, EPC D to G or no certificate, with an anniversary between 1/11/2022 and 31/10/2023	Adapted rent of 2022-2023 × (new index ÷ index of the month preceding that anniversary)	No factor: depends on the adapted rent
Every other lease	Good EPC classes, or more recent leases	Ordinary formula	100 %

For the record: the temporary 2022-2023 periods (ended)

Region	Period	Rule applicable at the time
Brussels	14/10/2022 → 13/10/2023	A, B, C, D: 100 % · E: at most 50 % of the indexation · F, G and no EPC: no indexation
Flanders	1/10/2022 → 30/9/2023	A+, A, B, C: 100 % · D: half of the increase · E, F and no EPC: no indexation
Wallonia	1/11/2022 → 31/10/2023	A, B, C: 100 % · D: 75 % of the increase · E: 50 % · F, G and no certificate: no indexation

During those periods, and only then, the calculation bore on a share of the increase. These percentages no longer apply to any indexation requested today.

Worked examples of the effective cap

For a base rent of €800/month, lease concluded and entered into force on 1 July 2020, indexed on 1 July 2026 (starting index June 2020: 110.05; new index June 2026: 139.08; ordinary formula: 800 × 139.08 ÷ 110.05 = €1,011.03):

Case	Ordinary formula	Correction	Indexed rent
Wallonia, EPC B	€1,011.03	none	€1,011.03
Wallonia, EPC G (anniversary of 1/7/2023 within the period)	€1,011.03	adapted-rent method	€962.74
Brussels, EPC D	€1,011.03	none	€1,011.03
Brussels, EPC G	€1,011.03	× 0.952238571	€962.74
Flanders, EPC D	€1,011.03	× 0.976119286	€986.89
Flanders, EPC F	€1,011.03	× 0.952238571	€962.74

For a lease concluded and entered into force on 1 July 2024 (so after the cut-off dates), in Brussels as in Flanders, no correction applies whatever the class: 800 × (139.08 ÷ 131.92) = €843.42 on 1 July 2026.

For your exact situation, the calculator automatically applies the right correction according to the region, the EPC and the dates of conclusion and entry into force.

Why has Belgian law not set a federal cap?

Three historical reasons:

1. Contractual balance — indexation is conceived as a simple update of the initial rent in the face of inflation. Setting it at a cap would amount to organising a real loss of value for the landlord, which discourages rental investment.
2. Macro-economic logic — the health index already excludes the most volatile components (fuels, tobacco, alcohol). The 1993 legislator considered this weighting sufficient to absorb shocks.
3. Regional subsidiarity — since the sixth state reform (2014), the regions are competent in housing matters. They can therefore modulate the rules through their own mechanisms (e.g. EPC correction factors), making a federal cap redundant.

And exceptional measures (freeze)?

In periods of extreme inflation (>5 % annual), the legislator can intervene punctually to freeze or cap indexation. This happened in the three regions:

• Wallonia: from 1 November 2022 to 31 October 2023, limitation for EPC D (75 % of the increase), E (50 %) and F, G or no certificate (no indexation); the effect remains anchored through the special method of the decree of 19 October 2022
• Brussels: from 14 October 2022 to 13 October 2023, at most 50 % of the indexation for EPC E and no indexation for EPC F, G or no EPC (ordinance of 13 October 2022); replaced since 14 October 2023 by the correction factor
• Flanders: from 1 October 2022 to 30 September 2023, half of the increase for EPC D and no indexation for EPC E, F or no EPC (decree of 3 October 2022, article 3); replaced since 1 October 2023 by the correction factor (article 4)

These measures are temporary in their principle, but their effects were made permanent for the leases concerned. In September 2026, no freeze measure is in force: only the permanent regional rules described above remain.

Special case: negative indexation

Theoretically, if the health index drops between signature and anniversary date (deflation), the formula produces a rent lower than the initial rent. Whether that decrease is mandatory is debated, and we know of no rule that settles it:

• First reading: negative indexation is applicable (the formula is neutral)
• Second reading: indexation is a right, so the landlord can waive an unfavourable result
• Practice: the case is extremely rare; if it arises, consult a professional

In 2026, the question remains theoretical.

To go further

• Calculate the indexation and its exact cap — EPC correction applied automatically
• Indexation after 5 years — historical cumulation vs annual cap
• Can indexation be refused? — valid grounds related to EPC
• Wallonia indexation — 2022-2023 period and special method
• Brussels indexation — detail of the correction factor
• Flanders indexation — detail of the Flemish correction factor
• When can one index? — annual calendar
• Complete methodology — legal sources and formula

The « cap » is not a legal notion at the federal level. It is, however, an operational reality in Brussels and Flanders for leases predating October 2022 — and a durably anchored effect in Wallonia for D to G leases that went through the 2022-2023 period — and it is precisely the dwelling’s energy class that sets the threshold. This information is provided for guidance only and does not constitute legal advice.