📈 What Is Yearly Rent Indexation, and How Does It Affect My Rent?
In Belgium, your rent may be adjusted annually based on the cost of living, which is tracked by Statbel, the Belgian government institution. This is called rent indexation, and it happens every year on the anniversary of your rental agreement (⚠️not necessarily the anniversary of when you move in).
🏠 What Is Rent Indexation?
Rent indexation is a legal adjustment to your rent, reflecting inflation and changes in the cost of living.
It’s applied to the net rent (the rent excluding any additional charges) and happens on the contract anniversary date—the date your rental agreement was signed, not the day you moved in.
The adjustment is calculated using a simple formula:
📌 Basic rental price × New index ÷ Base index
Base Index → The index from the month before your contract was signed.
New Index → The index from the month before the contract anniversary.
Note: The indexation applies only to the net rent, not the additional charges like utilities or other fees.
📊 Example
Details | Roomie A | Roomie B |
Move-In Date | January 1st, 2024 | November 1st, 2024 |
Contract Anniversary | January 1st, 2025 | January 1st, 2025 |
Old Rent (Net) | €600 | €600 |
Base Index | 109.91 | 109.91 |
New Index | 115.20 | 115.20 |
New Rent (Net, from Jan 2025) | €628.88 | €628.88 |
Total Rent (with Charges) | €778.88 | €778.88 |
Roommate A is the first to move into the house, starting on January 1st, 2024. Their contract anniversary will be on January 1st, 2025, which is when rent indexation will take place for both roommates.
Roommate B replaces a departing roommate on November 1st, 2024. Even though their move-in date is later in the year, the contract anniversary for both roommates falls on January 1st, 2025, and their rent will be indexed using the same base index and new index.
This means both roommates’ rent will increase the same way, based on the same indexes, even though they moved in at different times.
📅 When Does Rent Indexation Take Effect?
The rent increase is applied on the anniversary of your contract. It will become effective one month after the official announcement. So, if the adjustment is announced in December, it would typically apply in January.
🖩 How Can I Calculate My Own Indexation?
To find out how much your rent will increase, you can use the Belgian Rent Indexation Calculator from the government:
For more information, check the specific guidelines for your region:
Brussels - Rental Price Indexation in Brussels
Flanders - Rental Price Indexation in Flanders