My flatmate left: I'm stuck paying alone

February 2025 — the departure

My name is Thomas, I am 25 years old and I work as a junior developer at a startup in Brussels. Since September 2024, I had been sharing a 2-bedroom flat in Ixelles with Hugo, a university friend. Total rent: 950 EUR, i.e. 475 EUR each, charges included. A good deal for the neighbourhood.

On 1 February 2025, Hugo told me he was moving in with his girlfriend in Ghent. “I’m leaving on 10 February.” Ten days’ warning for a permanent departure. No discussion, no offer to find a replacement.

On 10 February, Hugo collected his belongings. On the 11th, the flat was half empty and I was alone facing a 950 EUR rent — nearly half of my net salary of 2,100 EUR.

The joint liability clause

My first instinct was to re-read our shared housing lease. And there it was, a cold shower. Article 7, in small print:

“The flatmates are jointly and severally liable for payment of the full rent and charges.”

In plain terms: even though Hugo has left, I remain liable for 100% of the rent in the landlord’s eyes. The landlord can claim the full 950 EUR from me. That is the principle of joint liability: the landlord chooses whom to ask, and it is up to the remaining flatmate to pursue the other.

We had not signed a flatmate agreement. No written rules on notice between flatmates, no replacement procedure. A major mistake.

Mid-February — managing the crisis

On 15 February, I paid the full 950 EUR to avoid a default. My priority was not to be at fault vis-a-vis the landlord. I dipped into my savings.

Two actions in parallel:

1. Informing the landlord. I called Mr Berger, our landlord, that same day. He was understanding: “Find a new flatmate within 2 months and we’ll draft a lease amendment.” He agreed not to start proceedings as long as the rent was paid.

2. Formal notice to Hugo. On 22 February, I sent a registered letter to Hugo claiming:

• Reimbursement of his share of the February rent (475 EUR)
• Payment of his share of the March rent (475 EUR)
• Compliance with the 3-month notice period set out in the lease

Hugo replied by text: “I can’t afford it right now, we’ll see later.” I kept the text as evidence.

March 2025 — finding a replacement

I posted an ad on Immoweb, Facebook (Brussels flat-sharing groups) and Kotplanet. Within 10 days, I received 22 applications.

Selection criteria: net income above 1,500 EUR, stable employment or student with guarantor, non-smoker (lease condition). I arranged viewings for 6 people over 2 evenings.

I chose Maxime, 27, an engineer on a permanent contract. I presented his file to Mr Berger, who accepted after checking his payslips (net income of 2,600 EUR, i.e. more than 2.5 times his share of the rent).

On 1 April, we signed a lease amendment replacing Hugo with Maxime. Hugo’s rental guarantee was returned to him after deduction of his share of unpaid charges, and Maxime deposited his on the blocked account.

Recovering Hugo’s money

Hugo owed me 950 EUR (his share of February and March). After the registered letter went unanswered and several email reminders, I filed a claim at the justice of the peace in Ixelles in April 2025.

The judge ruled in June: Hugo was ordered to reimburse me the 950 EUR plus the registered letter costs (8.50 EUR). No additional damages because I did not have a flatmate agreement providing for an internal notice period.

Hugo paid in 2 instalments, in July and August. Case closed.

To fully understand your rights regarding rent sharing and each flatmate’s obligations, reading the lease is essential.

What I learned

Seven weeks of stress for a situation that could have been prevented by a single document. Here are my lessons:

1. Sign a flatmate agreement. This is a separate document from the lease, between flatmates only. It covers: notice of departure (minimum 2 months), the obligation to find a replacement, sharing of common charges, house rules. Without it, you have no framework in case of departure.

2. Negotiate the joint liability clause. In Brussels, since the 2018 ordinance on shared housing, each flatmate can terminate their part of the lease with 3 months’ notice. But joint liability can survive departure if the lease provides for it. Ask for a clause limiting joint liability to 3 months after effective departure.

3. Build a safety reserve. I had 1,200 EUR in savings when Hugo left. Without it, I would have defaulted on payment from the first month. Plan for at least 2 months’ total rent in reserve.

4. The landlord is often an ally. Mr Berger could have demanded immediate payment and refused any arrangement. By informing him early and proposing a plan (find a replacement within 2 months), I obtained his cooperation. Transparency pays off.

If you are in shared housing, take the time to structure your lease properly. See our guide on leases and our other tenant testimonies to avoid unpleasant surprises.