Co-tenancy is attracting more and more tenants — students, young workers, lower-income households. For landlords, it offers real advantages: combined rents that are more attractive, continuous occupation, and shared risk. But it also brings a series of legal, fiscal, and practical pitfalls. The Walloon Decree of 15 March 2018 on residential leases (Articles 65 and following) governs the matter strictly. A tour of the five essential watchpoints that every property manager must master.
Pitfall 1: choosing between a single lease and individual leases
The first structural decision comes even before signing: should you have a single lease signed by all co-tenants, or individual leases signed by each tenant covering their room and the shared areas?
The single lease: the secure solution
With a single lease, each co-tenant is party to the same contract. This is the most protective arrangement for the landlord, particularly regarding joint liability. It simplifies administration: one contract, one statement of charges, one legal counterparty (even if there are several individuals).
Individual leases: flexibility at the cost of complexity
Each co-tenant signs their own lease covering their room, with shared use of common areas. This arrangement offers more flexibility during tenant changeovers (no approval formality required), but:
- It complicates management (a separate statement for each co-tenant, multiple inspections)
- It weakens the landlord's guarantees (no natural joint liability between co-tenants)
- It creates no legal bond between the co-tenants themselves
Practical recommendation: always opt for a single lease that expressly states joint liability between co-tenants. This is the arrangement that works best in practice and reduces risk in the event of one tenant defaulting.
Pitfall 2: the co-tenancy pact — the document that is often forgotten
The Walloon Decree introduces a concept that landlords often overlook: the co-tenancy pact (Article 72). This is an agreement concluded between the co-tenants themselves — not with the landlord — governing their communal life and internal relations.
Typical content of a pact
Under Article 72 of the Decree, co-tenants may agree among themselves on:
- The allocation of rent and charges
- Rules for communal living (use of shared spaces, maintenance, guests)
- Procedures for a co-tenant's departure and the search for a replacement
- The conditions under which a co-tenant may withdraw from the lease
Why landlords should take an interest in it
The landlord is not party to the pact. But a well-drafted pact considerably reduces disputes that could rebound on the landlord:
- In case of payment default, a pact specifying each share makes it easier to identify the defaulting co-tenant
- A pact that governs departures (internal notice periods, replacement procedure) reduces the risk of a vacancy
- Clear rules for communal living limit neighbourhood disturbances
Watch out for the hierarchy
The pact cannot derogate from the mandatory provisions of the lease or the Decree. If the pact allows one month's notice but the lease requires three months, the lease prevails as far as the landlord is concerned. The departing co-tenant might incur liability towards their co-tenants, but the landlord is not bound by the pact's shorter notice period.
Practical tip: at the time of signing, provide co-tenants with a pact template or explicitly invite them to draft one. Keep a copy for reference in case of a dispute.
Pitfall 3: joint liability — shield or illusion?
Joint liability is the great strength of a co-tenancy lease: it allows the landlord to claim the full rent from any co-tenant, regardless of the agreed share between them.
The key rule: joint liability is not presumed
Caution: under Walloon law, joint liability does not apply automatically. It must be expressly stipulated in the contract. If the lease does not contain a joint liability clause, the landlord can only claim each co-tenant's individual share — which can prove catastrophic if one of them becomes insolvent.
The recommended wording
Make absolutely sure the clause appears in the contract, in clear terms. A standard formulation:
"The tenants are jointly and indivisibly liable for the payment of rent, charges, and any indemnity due under this lease."
A frequent fiscal pitfall
Joint liability can be compromised when one co-tenant departs. Some contracts provide for an automatic release of joint liability on departure, which can deprive the landlord of an essential guarantee in respect of debts existing at the time of departure.
Explicitly provide in the lease that the departing co-tenant remains jointly liable for rent and charges due up to the effective date of their approved replacement.
Pitfall 4: domiciliation — the underestimated fiscal trap
This is probably the most recurring problem encountered by landlords of co-tenancy properties. And one of the least well understood.
Single person or cohabitant: why it changes everything
In Belgium, the distinction between a single person and a cohabitant for the purposes of social benefits regulations (unemployment, CPAS, health insurance, etc.) is decisive. A co-tenant registered at the same address as another may be treated as a "cohabitant" by fiscal and social institutions — with an impact on their benefits and tax advantages.
The pressure on the landlord
This creates pressure on the landlord: some co-tenants ask not to be registered at the property address in order to retain their single-person status and receive higher benefits. Others ask the landlord to declare a situation that does not reflect reality.
The golden rule: never interfere
Absolute recommendation: never become involved in your tenants' domiciliation arrangements. Remind them in writing that:
- Domiciliation is their exclusive responsibility
- It must reflect their actual situation
- The lease clearly states whether it is authorised or not
Fiscal impact on the landlord
Domiciliation also has an impact on your own tax position. If no occupant is registered at the property (which can happen when all co-tenants refuse to register), the property may be treated for tax purposes as not occupied as a resident's principal residence — with potential consequences: vacancy tax, loss of abatements, reclassification.
Pitfall 5: tenant changeover — the most delicate situation to manage
The departure of a single co-tenant during the lease is one of the most complex situations. The Walloon Decree provides a specific procedure:
The legal replacement mechanism
When a co-tenant wishes to leave the property:
- They notify their departure to the landlord
- The remaining co-tenants must propose a replacement within a contractually agreed period (failing which, a reasonable period applies)
- The landlord has an approval right over the replacement who meets certain conditions (solvency, no adverse tenancy record, etc.)
- If no replacement is found, the remaining co-tenants may either take over the full lease or terminate it under the conditions set out by the Decree
What must be regulated contractually
- The notice period (e.g. 3 months minimum)
- The presentation formalities for the candidate (CV, pay slips, guarantor)
- Objective approval criteria (solvency, clear tenancy record)
- The effect of the departure on joint liability for pre-existing debts
Inspection and rental deposit
When a single co-tenant departs, should a partial exit inspection be drawn up? Should the rental deposit (often paid as a lump sum) be partially refunded?
Our recommendation: include a clause in the lease stating that:
- The rental deposit remains fully constituted until the end of the lease
- The final exit inspection will only take place when the last co-tenant departs
- An interim contradictory inspection between co-tenants is preferable to establish internal responsibilities
In conclusion
Co-tenancy in Wallonia offers real opportunities for landlords, but it requires contractual rigour and heightened vigilance on several fronts:
- Explicit joint liability in the lease
- Regulated replacement procedure
- Neutrality on domiciliation issues
- Rigorous management of the rental deposit
A solid lease, combined with a coherent co-tenancy pact between the tenants, is the landlord's best asset before opening their property to this type of occupation. The two documents form a complementary pair: the lease protects the landlord, the pact organises the tenants' internal life.
For further reading, see also our article on rental deposits in Wallonia, which details the rules for constituting, managing, and releasing the deposit — a particularly critical topic in co-tenancy where tenant turnover complicates the refund process.
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