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Adding a person to an existing lease in Belgium

How to add a co-tenant, spouse or family member to an existing lease in Belgium. Procedure, amendment, legal and tax consequences.

EH Par Edouard Hennin 3 min de lecture Mis a jour le May 28, 2026

Common situations

Several situations may require adding a person to an existing lease:

  • Moving in together: your partner moves in and you want them to become a co-tenant
  • Legal cohabitation: you enter into legal cohabitation and the other person must appear on the lease
  • Marriage: the spouse’s rights depend on the Region and type of lease
  • Co-tenancy: a new flatmate joins the household
  • Family: an adult child or a parent moves in

The procedure differs depending on whether you want to add a co-tenant (with the same rights and obligations as you) or simply declare an occupant (who has no tenancy rights).

For the specific rules on co-tenancy, consult our dedicated guide.

Procedure to follow

Step 1: Inform the landlord

Contact the landlord in writing (email or letter) to inform them of your intention. The landlord has the right to refuse the addition of a co-tenant for a reasonable ground (insufficient solvency, overcrowding of the property).

Step 2: Verify solvency

The landlord may ask the new co-tenant for the same documents as for a prospective tenant: payslips, employment contract, identity document.

Step 3: Draft an amendment

An amendment to the lease is signed by the landlord, the initial tenant and the new person. The amendment modifies the lease clauses concerning the tenants.

Step 4: Register the amendment

The amendment must be registered with the FPS Finance within 2 months (free for primary residence leases). Registering the lease protects the new co-tenant in case of sale of the property.

The lease amendment

The amendment must state:

  1. The parties: landlord + existing tenant(s) + new person
  2. The purpose: addition of [name] as co-tenant from [date]
  3. The modifications: the new co-tenant assumes the same rights and obligations as the initial tenant
  4. The joint liability clause: specify whether joint liability extends to the new co-tenant (recommended for the landlord)
  5. Insurance: the new co-tenant must be covered by home insurance
No amendment = no rights

Without a signed and registered amendment, the added person has no tenancy rights. In the event of separation, they cannot remain in the property or request continuation of the lease in their name.

For the initial tenant

  • They remain co-tenant and retain all their rights
  • The joint liability clause now applies to both co-tenants
  • In case of departure, they must give notice in accordance with the lease

For the new co-tenant

  • They acquire the same rights as the initial tenant (right to remain, renewal)
  • They are jointly liable for rent and charges
  • They must be covered by home insurance

In Belgium, the spouse or legal cohabitant benefits from specific protection: even if they do not appear on the lease, they have the right to remain in the property in case of separation. This protection is provided by the Civil Code (Article 215) for spouses and by the law of 23 November 1998 for legal cohabitants.

To formalise the addition of a person, use our online lease generator which automatically generates the lease amendment. For more information, consult our guide on residential leases in Belgium.

Verifie & redige par
Edouard Hennin
Real estate expert since 2018, Edouard supports Belgian landlords and tenants through their rental processes. He oversees the writing of every guide in collaboration with the legal team and ensures all content reflects current legislation in Brussels, Wallonia and Flanders.
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Publie May 19, 2026
Derniere verification May 28, 2026
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