For tenantsFlatsharing in Belgium: the pact, joint liability, and one flatmate leaving
One joint lease or individual leases, joint-and-several liability, a flatshare pact, domicile, charges: what sharing really commits you to, and how it differs by Region.
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Flatsharing is not simply renting together. Since residential-lease powers were regionalised, Brussels and Wallonia have created a dedicated flatshare regime, with a specific contract and a compulsory document between the flatmates. Flanders took a different route: no separate "flatshare" contract, but precise rules on medehuur, how a co-tenant joins and leaves. The practical consequences differ, and you need to know which set applies before you sign.
One joint lease, or several individual ones?
Two structures coexist, and they bind you in entirely different ways.
The joint lease (a single contract, signed by all the flatmates). This is the dominant form when sharing a flat or a house. You are all tenants of the whole property. It is also the form in which joint-and-several liability bites.
Individual leases (one contract per room, between the owner and each occupant, with shared use of the common areas). You rent only your room. In principle you are not liable for the others' debts. This is the model of purpose-built rooming houses and many student digs, see the student lease.
The question to ask the owner before anything else: "Is this a flatshare lease with a solidarity clause, or an individual lease per room?" The answer changes everything.
Joint-and-several liability: what it really means
In a joint lease, the solidarity (or indivisibility) clause means that each flatmate answers for the whole rent and charges, not just their share. It is not boilerplate.
Concretely: rent of €1,200, four flatmates, €300 each. If one stops paying, the owner can claim €1,200 from any of the other three, the one they judge most solvent, without first pursuing the defaulter. Whoever pays must then chase the defaulting flatmate themselves. In short: solidarity transfers the insolvency risk from the owner to you.
Under the Brussels and Walloon flatshare regimes, solidarity between flatmates is the rule. In Flanders, all tenants who sign the same lease are jointly and indivisibly liable to the landlord. The practical conclusion is the same everywhere: you do not pick flatmates lightly. You are not just sharing a kitchen, you are sharing a debt.
The flatshare pact
In both Brussels and Wallonia, the dedicated regime requires a flatshare pact (pacte de colocation / samenhuurpact) between the flatmates, separate from the lease (in Wallonia, no later than the signing of the lease). The owner is not a party to it: it is an agreement among yourselves.
It settles what the lease ignores:
- the split of rent and charges (equal shares or weighted by room size);
- the deposit: who paid in what, how the leaver is reimbursed, and how damage caused by one of you is charged;
- an inventory of the shared furniture, and who owns it;
- upkeep and cleaning of the common areas;
- insurance, including fire insurance, and the water, gas and electricity contracts;
- the procedure on arrival or departure: internal notice, finding a replacement, how their arrival is accepted;
- how disputes between you are settled.
In Brussels, flatmates have an interest in registering the pact, to give it a certain date. In Flanders such a pact is not required; write one anyway. A one-page document signed by everyone will head off most conflicts and stands as evidence between flatmates.
One flatmate leaving: the real issue
This is where the Regions diverge most, and where precision matters. The common principle: the departing flatmate gives notice, to the owner and to the other flatmates, and is released once replaced. What changes is the period, and what happens without a replacement:
| Brussels | Wallonia | Flanders | |
|---|---|---|---|
| Leaver's notice | 2 months, at any time, no indemnity; copy to the flatmates by registered post | 3 months, served on the landlord and the flatmates at the same time | 3 months, for themselves only, no indemnity; the lease continues with the others |
| Released if… | an accepted replacement has signed an addendum before the notice ends, or they prove an active and sufficient search | the landlord and flatmates approve the replacement, which they may only refuse on just grounds | a new co-tenant replaces them |
| No replacement | their obligations and solidarity end no later than six months after their notice takes effect | released after the 3 months, against an indemnity of three times their share of the rent, paid to the flatmates | the landlord can still claim rent from them for up to six months after they leave |
Details: in Brussels, an "active and sufficient search" means, for example, posting the room on several websites, sharing it on social media, organising viewings. In Flanders these rules cover co-tenants who are neither married nor legal cohabitants; a married or legally cohabiting couple follows a different mechanism. And in both Brussels and Wallonia, once half of the signing flatmates have left without being replaced, the landlord may end the lease with six months' notice.
Two reflexes that will save you:
And the deposit? It stays blocked until the lease ends. The departing flatmate does not get "their" share back from the bank: in practice the incoming flatmate buys out the leaver's share. The flatshare pact must set that out in black and white; see also the rental deposit.
Domicile, cohabitant status, charges
Domicile. Every flatmate registers at the address with the municipality. That is an obligation, not an option: your main residence must match where you actually live. The steps are in formalities on arrival.
Cohabitant status. This is the least understood consequence, and the most expensive. Living with others at one address can change your position in the social-security system, unemployment benefit or integration income, because the "cohabitant" rate is lower than the "single person" rate. If you receive a benefit, check before moving in with your paying body or the public welfare centre: the question is not theoretical, and a correction may be retroactive. The rules and how they are applied change over time: assume nothing, ask.
Charges. Decide from the outset whether they are fixed (a flat monthly amount) or actual (provisions plus an annual reconciliation against invoices), see rental charges. In a flatshare, actual charges are fairer but require someone to keep the accounts: name a person in the pact. Meters (water, electricity, gas) must be read at every arrival and departure, dated and photographed.
Finding a flatshare
For a room in an existing flatshare, Appartager is the most common first stop. If you are setting up a flatshare as a group and looking for a whole house or flat let directly by its owner, Domilinko is a Belgian peer-to-peer rental site with no intermediary: listings carry a verified EPC certificate, owners' identities are verified, and the move-in inspection is done jointly, with photos and meter readings, which protects the whole group when the keys are handed back.
Checklist before signing
A flatshare that goes well is almost always one where those seven answers were written down before anyone moved in.
Official sources
- Brussels-Capital Region: rental contracts guide: official model leases for Brussels, including the flatshare lease.
- Brussels Housing brochure on residential leases (January 2025): chapter on flatsharing, the pact and a co-tenant leaving (in French).
- SPW Logement: flatsharing: the Walloon flatshare regime (in French).
- Vlaanderen.be: during the lease: co-tenancy (medehuur), subletting and assignment in Flanders (in Dutch).
Frequently asked questions
Am I liable if my flatmate does not pay their share?
Under a joint lease, yes: solidarity is the rule for flatshares in Brussels and Wallonia, and in Flanders all tenants who sign the same lease are jointly liable. So the owner can claim the whole rent from any flatmate. With individual room leases, no: you owe only your room. Check which type you are signing.
Is the flatshare pact compulsory?
In Brussels and Wallonia, the dedicated flatshare regime requires a pact between the flatmates, separate from the lease; in Wallonia, no later than the signing of the lease. In Flanders it is not required, but it remains strongly advisable: it fixes the split of rent and charges, the fate of the deposit, house rules and the departure procedure. It is the only document that protects you from each other.
How do I leave a flatshare without remaining liable for the rent?
Give written, dated notice to the owner AND the flatmates, and find an accepted replacement. In Brussels, notice is two months; without a replacement you are released if you prove an active search, and at the latest six months after your notice takes effect. In Wallonia, three months' notice; without an approved replacement, you are released by paying the flatmates three times your share of the rent. In Flanders, three months' notice; without a replacement, the landlord can still claim rent from you for six months. Then have your departure recorded in a signed addendum.
Does flatsharing change my benefits?
Possibly. Living with others at one address can move you from the « single » rate to the lower « cohabitant » rate for certain benefits (unemployment, integration income). If you receive a benefit, ask your paying body or the public welfare centre before moving in: a correction may be applied retroactively.
How do I get my share of the deposit back when I leave?
Not from the bank: the account stays blocked until the lease ends and is only released on a written agreement of all parties or a judgment of the justice of the peace. In practice, the incoming flatmate buys out your share on the day they arrive. Write it into the flatshare pact, with the exact amount each person paid in.