No obligation to find a replacement

Quick answer

Yes, a co-tenant can leave without finding a replacement. Belgian law does not require a co-tenant to provide a substitute before departing. The co-tenant gives 3 months’ notice individually. However, with a solidarity clause, they remain jointly liable for the full rent until the landlord formally releases them.

The co-tenant’s right to leave follows the standard termination rules:

The critical issue is the solidarity clause — if present, it creates ongoing liability even after departure.

The solidarity clause problem

If the lease contains a solidarity clause (clause de solidarite):

SituationConsequence
Co-tenant leaves, no releaseRemains liable for full rent
Landlord signs releaseCo-tenant is freed from obligations
Remaining co-tenants stop payingDeparted co-tenant can be pursued
New co-tenant joins (with landlord’s agreement)May release departing co-tenant
Always get a written release

If you are leaving a shared tenancy with a solidarity clause, insist on a written release from the landlord before departure. Without it, you remain liable for the full rent — not just your share — until the lease ends entirely.

Without a solidarity clause, the departing co-tenant is only liable for their own share of rent and charges during their occupation period.

Regional co-tenancy frameworks

All three Belgian regions have introduced specific co-tenancy legislation:

  • Co-tenancy pact (pacte de colocation): a legally recognised document that specifies rules for departures, replacements, and charge allocation
  • Replacement mechanism: some regions provide a structured process for finding and approving replacements
  • Limited solidarity: regional rules may limit the scope and duration of solidarity obligations

The co-tenancy pact is strongly recommended — it prevents most disputes by clearly defining the rules for departures.

Regional specifics

Brussels-Capital Region

The Ordinance of 27 July 2017 provides a specific co-tenancy framework. The departing co-tenant must give 3 months’ notice. The co-tenancy pact can specify replacement procedures. Solidarity is limited to the departing co-tenant’s share plus the share of one other co-tenant.

Wallonia

The Decree of 15 March 2018 introduced co-tenancy rules similar to Brussels. The solidarity clause is limited in scope to protect departing co-tenants.

Flanders

The Flemish Housing Rental Decree of 9 November 2018 provides the most detailed co-tenancy framework, including a structured replacement mechanism. The departing co-tenant can propose a replacement, and if the landlord refuses without valid reason, the departing co-tenant is released from solidarity.