What is a formal notice?

Quick answer

A formal notice (mise en demeure) is a registered letter that officially demands the recipient to fulfil a specific obligation. It is a prerequisite to court action in most tenancy disputes. It must clearly state the facts, the legal obligation, the deadline (usually 15 days), and the consequences of non-compliance.

In Belgian tenancy law, the formal notice serves several purposes:

  1. Creates a written record: proves that the other party was informed of the issue
  2. Sets a deadline: gives the recipient a reasonable period to comply
  3. Demonstrates good faith: shows the court that you attempted to resolve the matter amicably
  4. Triggers legal consequences: interest may start running from the date of the formal notice

The formal notice is not a court document — it is sent by the party themselves (landlord or tenant) via registered post.

How to draft a formal notice

Essential content

A formal notice must contain: identification of sender and recipient, date, description of the facts, reference to the relevant legal obligation or lease clause, a reasonable deadline for compliance (typically 15 days), and a clear statement of the consequences if the obligation is not met.

Structure of a formal notice:

SectionContent
HeaderSender and recipient identification, date, “Formal notice” (mise en demeure)
FactsClear description of the issue (unpaid rent, unrepaired damage, etc.)
Legal basisReference to the lease clause or legal provision
DemandSpecific action required (pay, repair, cease, etc.)
DeadlineReasonable period, usually 15 days
ConsequencesCourt action, lease termination, damages claim
Sending methodRegistered letter with acknowledgement of receipt
Warning

A formal notice sent by ordinary post or email is valid but harder to prove. Always use registered post to ensure proof of sending and receipt. Keep a copy of the letter and the sending receipt.

What happens after the formal notice?

If the recipient complies within the deadline, the matter is resolved. If not, the sender can escalate:

  • Justice of the peace: the competent court for all tenancy disputes in Belgium. Filing is relatively simple and costs are moderate
  • Conciliation: a free preliminary hearing before the justice of the peace, which can often resolve disputes without a full trial
  • Bailiff: for enforcement of payment or eviction (only after a court decision)

The formal notice is an important piece of evidence in court. The judge will check whether the claimant gave the other party a fair opportunity to comply before initiating proceedings.

In practice, many disputes are resolved at the formal notice stage, as the recipient realises the sender is serious about enforcing their rights.

Regional specificities

Brussels-Capital Region

The ordinance of 27 July 2017 does not impose specific formal notice requirements beyond general law. Brussels tenancy disputes are handled by the justice of the peace of the relevant canton.

Walloon Region

The decree of 15 March 2018 follows the same general principles. Some specific Walloon lease clauses may require a formal notice before certain actions (e.g., early termination).

Flemish Region

The Flemish Housing Rental Decree of 9 November 2018 requires formal notice (ingebrekestelling) in several situations, such as requesting essential repairs. The letter must be sent by registered post.