In Belgium

A formal notice (mise en demeure / ingebrekestelling) is a formal written demand requiring the recipient to fulfil their obligations within a specified period. It is the mandatory first step before most legal proceedings in Belgian rental law.

How it works

Content. The letter must state: the breach identified, the obligation to be fulfilled, a reasonable deadline (typically 8 to 15 days), and a warning that legal action will follow if not remedied.

Method. Sent by registered letter with acknowledgement of receipt.

Legal effects. Triggers late-payment interest from the date of receipt and demonstrates good faith to the court.

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Good to know
A formal notice is not a judgment — it has no enforceable force. If the recipient does not comply, the sender must still file with the justice of the peace to obtain a binding decision.

Practical example

A tenant has not paid rent for 2 months. The landlord sends a formal notice by registered letter requiring payment of 1,500 EUR within 15 days. The tenant does not pay. The landlord files with the justice of the peace, presenting the formal notice as proof of prior attempts.