Filled indexation letter example
Pedagogical template with real example values — landlord Marie Dupont, tenant Jean Vandenberghe, rent €850, EPC C, Brussels lease signed in 2021. Ideal to understand the expected structure before filling in your own letter.
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Avenue Louise 367
1050 Brussels
RECIPIENT
Jean Vandenberghe
Rue Haute 142
1000 Brussels
Subject: Annual rent indexation — anniversary date 1 July 2026
Dear Sir or Madam,
In accordance with article 1728bis of the Belgian Civil Code, I hereby notify you of the annual indexation of the rent relating to the property located at Rue Haute 142, 1000 Brussels, subject of the lease signed on 14 June 2021.
Applied formula: Initial rent × (New index ÷ Base index) × EPC coefficient.
That is: 850.00 × (132.47 ÷ 110.99) × 100 % = €1,015.83.
Variation: + €165.83/month.
Yours faithfully,
Signature,
Marie Dupont
Detail of the elements of the letter
1. Landlord header (top-left)
Full name of the landlord on the first line (in bold). Full address on the following lines (street, postal code, city). Optional: professional email.
2. Metadata (top-right)
Date of the letter in capitals, on the first line. Internal reference (e.g. REF · IDX-2026)
on the second line. Useful to retrieve the letter in your archive.
3. Title bar
Centred frame that clearly announces the subject of the letter. Format: "Annual rent indexation — [region]". Allows the tenant to instantly understand the content.
4. Recipient block
Tenant's name (in bold) followed by the notification address. If the tenant receives their mail at an address different from the rented property, it is this notification address that appears here.
5. Subject and salutation
The subject must clearly mention the indexation and the effective date. The formula "Dear Sir or Madam," respects Belgian conventions even if you personally know the tenant.
6. Explanatory body
Reference to article 1728bis of the Civil Code + property address + key dates of the lease. This technical precision serves as legal proof in case of dispute.
7. Detailed calculation block
The calculation block is essential. It must display:
- Initial rent (base amount of the lease)
- Base health index (month preceding the signature) — Statbel value
- New health index (month preceding the anniversary) — Statbel value
- Energy class + EPC coefficient where applicable
- New monthly rent (result) in bold and well visible
8. Explicit formula
Repeat the applied mathematical formula + the numerical calculation. This allows the tenant to verify themselves with a simple calculation.
9. Signature
Mention "Signature" in italics, followed by the landlord's name. On the printed version, the landlord signs by hand above their typed name.
To generate your own personalised letter
Our calculator or our generation wizard produce a PDF identical to this example, but with your real data (your names, your lease, your EPC).
Frequently asked questions
What distinguishes this example from the other templates? + −
This example is pedagogical: all fields are pre-filled with concrete values (Marie Dupont landlord, Jean Vandenberghe tenant, rent €850, real Statbel indexes). Ideal to understand the structure and adapt to your situation.
Can I use this example as is? + −
No, it is an example document — it is marked as such in the PDF. To generate a real letter with your own data, use the calculator or the generation wizard.
Are the example values realistic? + −
Yes — Brussels lease signed in 2021 with EPC C, indexation on 1 July 2026, Statbel indexes close to reality. It is representative of a typical case of rental management in 2026.
How to use it for a concrete case? + −
Copy the structure (header, subject, body, calculation, signature), replace the example values with your own, recalculate with our calculator, and print. Or use the calculator directly to generate a ready-to-use PDF with your data.