Default Interest in Real Estate: When Do They Start to Accrue?

Imagine you are a property owner in Biscarrosse. You sell your holiday home with the help of a local estate agent. The sale is completed, the authentic deed is signed at the notary's office, but you consider the requested commission excessive. You decide not to pay immediately, thinking time is on your side. But what is the reality? From when does default interest start to accrue on this amount due?

This question, seemingly very technical, nevertheless affects thousands of property owners each year. In the jurisdiction of Mont-de-Marsan, where property transactions around the lakes of Parentis-en-Born and Biscarrosse are numerous, the answer can make the difference between a simple dispute and costly litigation. Default interest (the interest that compensates for late payment) sometimes represents significant sums over several months, or even years of proceedings.

The Court of Cassation's ruling of 27 February 1985 provides a clear answer to this question. In a few pages, the judges settled a debate that had long pitted sellers against estate agents. But what exactly does this change for you, as a property owner, tenant, or real estate professional? This is what we will break down together, with concrete examples drawn from my practice in the Landes.

The Facts: A Story That Happens Every Day

The story begins like so many others in our region. Mr. Dupont, owner of a beautiful villa in Parentis-en-Born, decides to sell it. He instructs the estate agency "Les Pins Dorés" to find a purchaser. The contract is clear: the commission amounts to 5% of the sale price, payable upon signing of the authentic deed. The agency finds a serious buyer, Mr. Martin, and the sale is completed at the notary's office on 27 October 1981.

But here's the catch: Mr. Dupont disputes the amount of the commission. He believes that certain services were not properly rendered and that an account needs to be settled between the parties. Rather than settling the invoice, he waits. The agency, for its part, insists on being paid. Months pass, relations become strained. Finally, "Les Pins Dorés" decides to sue Mr. Dupont to obtain payment of its commission.

The proceedings follow their course. The Court of Appeal, seized of the case, recognises the validity of the agency's claim. But it adds a detail that will change everything: according to it, default interest would only start to run from the date of its judgment, i.e., from the ruling, and not from the formal demand. Why? Because, according the appeal judges, the sum was not due before due to the account needing to be settled between the parties. In other words, as long as the dispute over the services rendered was not resolved, payment could not be demanded.

The estate agency is not satisfied with this decision. It believes it is losing several years of interest. It therefore decides to appeal to the Court of Cassation, arguing that the interest should have started to run from its first formal demand for payment. It is this position that the Court of Cassation will examine, in a landmark ruling.

The Court's Reasoning — Broken Down

The Court of Cassation, in its ruling of 27 February 1985, quashes the Court of Appeal's judgment. Its reasoning is based on a fundamental article of the Civil Code: Article 1153. This article states that "in obligations limited to the payment of a sum of money, damages resulting from delay in performance consist only of an award of interest at the statutory rate". But above all, it specifies that this interest runs "from the day of the formal demand for payment".

The judges of the Court of Cassation explain their position with great clarity. They first recall an essential principle: each claim retains its own character. Here, the estate agent's commission is a certain claim (whose amount is determined by the contract), liquid (its amount is precise) and due (it is payable). The fact that there might be an account to settle between the parties, with possible set-offs, does not change the nature of this claim.

In short, even if Mr. Dupont might have had claims to assert against the agency (for services not rendered, for example), this did not prevent the commission from being due. These claims could give rise to set-off (a mechanism where two debts partially cancel each other out), but they did not suspend the due date of the commission. The Court insists: "the claims existing on each side each retained their character and were subject to their own regime".

What few people know is that the Court considers that the initiating court document (the first writ of summons) constitutes a formal demand. As soon as "Les Pins Dorés" sued Mr. Dupont, it formally demanded payment. From that day, default interest must start to run. The Court of Appeal was therefore wrong to make it run only from the date of its own judgment. This decision confirms consistent case law: the formal demand for payment triggers the interest, even if the exact amount of the debt is disputed.

What This Changes for You — Concretely

This decision has very practical implications for all real estate players. Let's take concrete examples in our jurisdiction of Mont-de-Marsan.

If you are a selling property owner (landlord): be careful with late payment of commissions. Imagine you sell an apartment in Biscarrosse for €200,000, with a 4% commission (i.e., €8,000). If you dispute the payment and the estate agent sues you six months later, default interest will run from the date of the writ. At the statutory rate (approximately 3.5% in 2024), this represents about €140 in additional interest per year. Over two years of proceedings, you add €280 to your debt. undefined, I have come across cases where this interest represented several thousand euros on significant commissions.

If you are an estate agent or professional in the sector: this decision protects you. It allows you to claim interest from your first formal demand, even if the client disputes the amount. In Parentis-en-Born, where transactions on lakeside properties can reach high amounts, this protection is valuable. However, you must be vigilant: for interest to run, your claim must be certain (the amount must be determined or determinable by the contract).

If you are a purchaser or tenant: the principle also applies to you. For example, if you owe occupation indemnities or a balance of the price, and you delay payment, interest will run from the formal demand. How to react? The best is to regularise quickly, or failing that, to contest in writing specifying your arguments, to avoid interest accumulating unnecessarily.

Be careful however: this rule only applies to monetary obligations. For other obligations (such as carrying out works), the interest regime is different.

Four Tips to Avoid This Type of Dispute

• Draft clear and precise contracts: In any sales mandate or agency contract, explicitly state the amount of the commission, the conditions for its due date, and the payment terms. Avoid vague formulas like "commission to be agreed".
• Formally demand payment quickly and in writing: As soon as a payment is late, send a registered letter with acknowledgment of receipt specifying the amount claimed and the payment deadline. This letter constitutes the formal demand that triggers interest.
• Keep all evidence: Keep copies of contracts, invoices, correspondence, and proof of service delivery. In case of dispute, these documents will be essential.
• Consult a specialised lawyer before disputing a payment: Early consultation can help you avoid bad surprises regarding default interest. In the jurisdiction of Mont-de-Marsan, local customs can influence the interpretation of contracts.

Besoin d'un conseil personnalisé ? Contactez Maître Zakine — première consultation 30 min à 45€.

In-Depth Analysis: Related Case Law and Developments

The 1985 ruling is part of consistent case law from the Court of Cassation. Already, in a ruling of 4 January 1983 (No. 81-15.432), the Court had recalled that "default interest due because of delay in performing a monetary obligation runs automatically from the day of the formal demand". This position has been confirmed many times, notably in a ruling of 12 July 2011 (No. 10-17.082).

What is interesting is that this case law protects the creditor (the one to whom money is owed) against dilatory tactics by the debtor (the one who owes). Indeed, without this rule, a debtor could unduly dispute a claim to delay payment without suffering financial consequences. The Court of Cassation thus ensures the balance of contractual relations.

The trend of the courts is clear: they strictly apply Article 1153 of the Civil Code. Even when the claim is disputed, as long as it is certain, liquid and due, interest runs from the formal demand. For the future, this legal stability is reassuring for real estate professionals, who can anticipate the consequences of late payment.

In Practice: What to Do

Here is a checklist to guide you according to your situation:

1. If you owe an estate agency commission: Pay within the deadlines provided in the contract. If you dispute the amount, pay under reserve (specifying your reservations in writing) or quickly apply to the court to have the dispute resolved.

2. If you are an estate agent and a client does not pay: Send a formal demand by registered post at the first delay. Keep proof of sending and receipt. This formal demand triggers default interest.

3. If you are in dispute over a commission: Calculate default interest from the date of the first formal demand. Do not forget to claim it in your submissions to the court.

4. If you are negotiating a mandate contract: Have the due date of the commission specified. Ideally, provide for payment upon signing of the authentic deed, with a limited grace period.

5. In case of doubt: Consult a lawyer specialised in real estate law. One hour of consultation can save you years of proceedings and thousands of euros in interest.

Do you find yourself in a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →