You have found the right flat in Paris, Lyon or Nice, the price is agreed, and the notaire (French public officer in charge of conveyancing) is preparing the final deed. Then a new document lands on the pile: the building manager claims several thousand euros of unpaid charges de copropriété (co-ownership service charges) and warns that part of your purchase price may be frozen to pay the seller’s debt. For a foreign buyer, this is often the first contact with one of the most technical corners of French property law: the protection of the syndicat des copropriétaires (the co-owners’ association) when a flat changes hands.

French law gives the co-owners’ association powerful tools to recover arrears from the sale price itself, through a mechanism called opposition (formal notice served on the notaire to retain funds). But those tools are framed by strict deadlines, precise content requirements and recent case law that regularly punishes sloppy claims. This article explains, step by step, who pays what when a French flat is sold with charges in arrears, which papers a foreign buyer must demand before signing, and what remedies exist when the syndic (the building manager acting for the association) claims too much.

The rules below apply throughout France, including Paris and the Île-de-France, where high service charges in large copropriétés (residential co-ownership buildings) make these disputes particularly frequent and expensive.

I. Before the sale is signed: the certificate, the debtor-buyer check and the split of charges

Everything starts before the authentic deed. French law organises a preventive system: inform the buyer, identify who owes what at the date of the sale, and — since 2024 — block sales to buyers who already owe money to the same building.

A. The Article 20 certificate and the seller-buyer split of charges

When a co-ownership lot is sold for consideration, the seller is expected to hand the notaire a certificate from the syndic, less than one month old, confirming that the seller is free of any obligation toward the association. If that certificate is produced, the sale proceeds without retention. If it is not produced, the notaire must notify the transfer to the syndic by registered letter with acknowledgment of receipt within fifteen days of the transfer of ownership. This is the first paragraph of Article 20, I of the Law of 10 July 1965, in its version in force since 11 April 2024 (Article 20, Law No. 65-557 of 10 July 1965).

The statutory sentence is worth reading in full: “avis de la mutation doit être donné par le notaire au syndic de l’immeuble par lettre recommandée avec avis de réception dans un délai de quinze jours à compter de la date du transfert de propriété” (Article 20, Law No. 65-557 of 10 July 1965). In other words, service of the transfer notice by the notaire, within fifteen days of the transfer of ownership, is the trigger for everything that follows. Under Article 1583 of the Civil Code, ownership between seller and buyer passes as soon as the thing and the price are agreed, but in a French conveyance the authentic deed signed before the notaire fixes the practical date from which the fifteen days run.

A foreign buyer should therefore never treat the certificate as a formality. Ask the notaire, well before the signing date, whether the Article 20 certificate has been obtained, what balance it shows, and which financial years it covers. If the seller cannot produce it, part of the price may be retained after the sale, and the release of the funds will depend on an agreement with the syndic or on court proceedings. A buyer financing the purchase with a foreign mortgage should warn the lender: a retention on the price does not reduce the price, but it changes the flow of funds at completion.

The second question is who owes the current charges: the seller or the buyer. The answer is given by Article 6-2 of the Decree of 17 March 1967, in its version in force since 25 December 2025 (Article 6-2, Decree No. 67-223 of 17 March 1967). Three rules share the burden. First, payment of the provision due under the provisional budget (budget prévisionnel) falls on the seller. Second, payment of provisions for expenses outside the provisional budget falls on whoever — seller or buyer — owns the lot when the provision becomes due. Third, any surplus or shortfall revealed when the accounts are approved is credited or debited to whoever owns the lot when the general meeting approves the accounts.

A concrete example helps. Suppose the sale completes in March, the quarterly budget provision due in January was payable by the seller, and a major façade repair voted the previous year calls for funds in May: the May call is payable by the buyer, who now owns the flat. Conversely, if the annual accounts approved in June reveal that the seller underpaid during his ownership, the adjustment goes to the buyer’s account as current owner — which is why the parties routinely settle these adjustments between themselves through a prorata clause in the deed. Such a clause is valid, but Article 6-3 of the same decree recalls that any agreement departing from the statutory split binds only the parties to the sale, never the association. The syndicat always claims against whoever the statute designates, and the parties sort out the difference between themselves.

Practical tip for buyers signing from abroad: the compromis de vente (preliminary sale agreement) should list the documents the seller must deliver — the under-one-month certificate, the last three years of approved accounts, the annual statement of charges (décompte), and proof that no extraordinary works voted but not yet called remain hidden. An uninformed buyer who discovers after completion that the general meeting had voted heavy works before the sale has little leverage left, because the later calls will legally fall on the new owner.

B. The 2024 debtor-buyer check: a sale can now be blocked before it is signed

Since the Law of 9 April 2024, Article 20 has a second paragraph that foreign buyers — and especially buyers using a French société civile immobilière (SCI, a non-trading property company) — must know. Before the authentic deed is drawn up, the notaire notifies the syndic of the identity of the prospective buyer, including, for an SCI or a general partnership buying the flat, the names of the managers and shareholders, as well as their spouses or civil partners. Within one month, the syndic issues a certificate, also less than one month old, stating either that these persons do not own another flat in the same building, or, if they do, that none of them has ignored a formal demand to pay for more than forty-five days (Article 20, II, Law No. 65-557 of 10 July 1965).

The consequence is blunt: “Si le copropriétaire n’est pas à jour de ses charges au sens du 2° du présent II, le notaire notifie aux parties l’impossibilité de conclure la vente” (Article 20, Law No. 65-557 of 10 July 1965). In plain English, if the buyer — or, for an SCI buyer, one of its managers, shareholders, or their spouse or partner — already owes arrears in the same building and has ignored a formal demand for over forty-five days, the notaire notifies both parties that the sale cannot be completed.

This control bites in situations foreigners underestimate. An investor who already owns a studio in the same Paris residence and has stopped paying its charges while disputing them cannot simply buy the neighbouring flat through a newly formed SCI to start afresh: the SCI’s shareholders are screened too. A couple buying jointly should check both spouses’ positions, including flats owned before the marriage. And because the syndic has a full month to answer, the parties should trigger this notification early — ideally at the compromis stage — rather than discovering the blockage the week of completion, with a mortgage offer about to expire.

For the seller’s side, the mirror lesson is to keep proof of every payment: bank transfers with the lot reference, receipts from the syndic, and the formal demands received. If the syndic‘s certificate wrongly states that arrears exist, the sale-contract timetable collapses through no fault of the buyer, and only clean paperwork allows a quick correction or a court application.

II. After the sale: the syndic’s opposition on the price and the defences against excessive claims

When the certificate route has not cleared the debt, the statute gives the association a second weapon: intercepting the sale price in the notaire’s hands. This opposition (opposition on the price) is effective, but it obeys a strict timetable and demanding content rules that the Cour de cassation enforces without indulgence.

A. Fifteen days plus fifteen days: how the opposition works and what it must contain

The timetable runs in two steps of fifteen days. First, the notaire notifies the transfer to the syndic within fifteen days of the transfer of ownership. Second, within fifteen days of receiving that notice, the syndic may serve an opposition — an extrajudicial act (acte extrajudiciaire, served by a bailiff) at the elected address — to obtain payment from the funds of the sums still owed by the former owner. On pain of nullity, the opposition must state the amount and the causes (les causes, the legal and factual grounds) of the claim, and its effects are limited to the amount stated. The notaire releases the funds once the association and the seller agree on the sums due; without agreement, the notaire pays the retained sums to the association within three months of the opposition, unless the opposition is challenged in court. Any friendly or court-ordered payment or transfer of the price made in breach of these rules cannot be invoked against an association that validly opposed. Finally, a valid opposition automatically puts into effect the legal mortgage of Article 19-1 for the association’s benefit (Article 20, I, Law No. 65-557 of 10 July 1965).

Two points deserve emphasis for foreign parties. First, the money retained belongs to the price owed to the seller: the buyer has paid in full and is not asked to pay twice. The dispute is between the association and the former owner, with the funds frozen as security. Second, the three-month payment rule means a seller who disputes the claim must act fast and challenge the opposition in court within that window; silence leads to the funds being handed over.

The content of the opposition is where most disputes arise. Article 5-1 of the Decree of 17 March 1967 provides that only claims of the association that are actually liquidated and due (liquides et exigibles) at the date of the transfer may be counted, and that the opposition must state precisely, in four separate categories: the amount and causes of claims of the current year and the last two expired years; those of the two years before that; those secured by a legal mortgage but outside the privileged claims; and all remaining claims (Article 5-1, Decree No. 67-223 of 17 March 1967).

The Cour de cassation has given these requirements real teeth. In a ruling of 22 June 2017, the Third Civil Chamber quashed an appeal decision that had accepted a global opposition, holding: “l’opposition doit comporter le détail des sommes réclamées selon leur nature et préciser chacun des lots auxquels ces sommes sont afférentes” (Cass. 3rd civ., 22 June 2017, No. 16-15.195). In English: the opposition must break down the sums claimed by nature and identify each lot to which they relate (Cass. 3rd civ., 22 June 2017, No. 16-15.195). A single lump sum covering several lots, or mixing budget charges with exceptional works without distinction, fails this test.

A 12 October 2023 ruling refined the penalties. The Court held that failing to distinguish the four categories does not void the opposition itself, but it costs the association the benefit of the special legal mortgage of Article 2402 of the Civil Code: “constitue un manquement à une condition de forme de nature à faire perdre au syndicat le bénéfice de l’hypothèque légale spéciale prévue à l’article 2402 du code civil.” In other words, a poorly itemised opposition still freezes the funds, but the association loses its best security (Cass. 3rd civ., 12 Oct. 2023, No. 22-18.723).

The same 2023 decision added a second holding that directly protects sellers and, indirectly, buyers. Only claims that are genuinely liquidated and due at the date of transfer can support an opposition: charges for financial years whose accounts the general meeting never approved are not due and cannot be retained. The Court quashed the appeal ruling for including 2016 and 2017 charges without finding that a general meeting had approved them, recalling that budget charges and voted provisions become due upon demand only once approved by the meeting. A seller facing an opposition should therefore demand, for every euro retained, the meeting minutes approving the corresponding accounts or budget — and a buyer should ask the same question before completion, because unapproved back-years in the décompte signal a claim the association may be unable to enforce.

Foreign buyers can draw a simple checklist from this case law: require the itemised statement per lot and per financial year; verify that each year’s accounts were actually approved; check that the opposition, if any, was served within the fifteen-day window by extrajudicial act; and confirm the stated amount matches the certificate. Any gap is a reason to ask the notaire to hold the position until the syndic justifies the figures.

B. Time limits, securities and the buyer’s own remedies, including Paris specifics

Beyond the opposition timetable, three long-term rules shape every arrears dispute: the limitation period, the association’s securities, and the remedies of a buyer who inherits a degraded building.

Limitation first. Since 1 June 2020, Article 42 of the Law of 10 July 1965 refers personal actions between co-owners, or between a co-owner and the association, to the five-year regime of Article 2224 of the Civil Code (Article 42, Law No. 65-557 of 10 July 1965). That article provides: “Les actions personnelles ou mobilières se prescrivent par cinq ans à compter du jour où le titulaire d’un droit a connu ou aurait dû connaître les faits lui permettant de l’exercer.” In English: personal actions are time-barred after five years running from the day the holder knew, or should have known, the facts enabling the claim. This replaced the former ten-year period that the Cour de cassation once applied to charges recovery — a 17 November 1999 ruling famously held that recovery of variable, undetermined charges fell outside the old five-year Article 2277 and followed the ten-year personal-action period of the co-ownership statute (Cass. 3rd civ., 17 Nov. 1999, No. 98-13.114). Buyers reading old commentaries should update their references: the ten-year rule belongs to history, and the current period is five years from knowledge.

The knowledge-based starting point still matters enormously for buyers. In a 19 November 2015 decision, the Third Civil Chamber quashed a ruling that had started time running from the appearance of building defects, without examining whether the buyer companies had only learned the cause of the disorders during the court-ordered expert assessment (Cass. 3rd civ., 19 Nov. 2015, No. 14-17.784). A foreign buyer who discovers after completion that the common parts are seriously defective — leaking roof, failing lift, structural cracks — and sues the association to perform repair works on the common parts can therefore argue that time runs from when an expert report revealed the true cause, not from the first visible stain. The duration is now five years, but the starting-point reasoning survives under Article 2224’s knowledge test.

Securities next. Article 19 of the Law of 10 July 1965 grants the association a legal mortgage (hypothèque légale) over each debtor’s lot for claims of any kind, whether provisions or final payments; the syndic may register it without prior meeting authorisation after an unsuccessful formal demand, and no registration may cover claims due for more than five years (Article 19, Law No. 65-557 of 10 July 1965). Article 19-1 adds that a valid opposition automatically implements that mortgage. At the level of the Civil Code, Article 2402, 3° attaches a special legal mortgage to the association’s claims “relatives à l’année courante ainsi qu’aux quatre dernières années échues” — for the current year and the last four expired years. The practical meaning for a buyer: even if the opposition was defective in form and lost the mortgage benefit, as in the 2023 case, the association may still hold a registered mortgage for recent years that will appear in the mortgage statement (état hypothécaire) ordered by the notaire. Always ask for that statement and read it: a registered legal mortgage survives the sale and clouds the title until discharged.

The seller is not without weapons either. Article 1342 of the Civil Code recalls that payment, once due, discharges the debtor — so a seller who pays the certified balance before completion removes the very basis of any opposition. And a defaulting co-owner facing a mortgage registration can apply to the president of the judicial court, ruling under the fast-track procedure on the merits, for full or partial discharge against a sufficient payment offer or equivalent guarantee. For a Paris flat, that application goes to the Paris judicial court (tribunal judiciaire de Paris), which handles these co-ownership incidents routinely; foreign sellers should budget for representation at that hearing rather than ignoring the registration and discovering it at the next sale.

For buyers already trapped — funds retained, sale completed, association demanding years of alleged arrears — the defence follows the order of this article in reverse. First, attack the opposition’s form: lump sum without breakdown by nature, no allocation per lot, missing four-category distinction, service outside the fifteen days or by simple letter instead of extrajudicial act. Second, attack the substance: demand proof that each year’s accounts were approved, because unapproved years are not due. Third, raise the five-year limitation for the oldest years, counting from what the association knew. Fourth, verify the mortgage registrations and seek discharge of anything stale. Each of these steps requires documents a foreign owner can obtain from France: meeting minutes, statements of account, the opposition writ itself, and the mortgage statement. Ask the notaire who handled the purchase to keep certified copies of all of them; eighteen months later, when the dispute peaks, those papers are the case.

Two Paris and Île-de-France specifics close this section. First, in large Parisian residences with professional managers, the Article 20 certificate and the pre-sale buyer screening are processed by specialised transfer departments; allow three to six weeks between the compromis and completion for these papers, longer than the statutory minimums suggest. Second, jurisdiction follows the building: for a Paris flat, challenges to an opposition, applications for discharge of a mortgage, and claims for common-part works all go to the Paris judicial court, and instruction is conducted in French with strict procedural deadlines. A non-French-speaking owner needs counsel who can receive service, calendar the fifteen-day and three-month windows, and correspond with the syndic in French from day one. Further guidance on choosing representation is available from our real estate law team in Paris 17th, which assists foreign owners before the Paris courts.

Conclusion

Buying a French flat with unpaid co-ownership charges is manageable, but only with paperwork discipline. Before signing, demand the under-one-month Article 20 certificate, verify the split of provisions under Article 6-2, screen every buyer-side name under the 2024 debtor-buyer check — including SCI managers, shareholders, spouses and partners — and confirm that each past year’s accounts were approved. After the sale, calendar the two fifteen-day windows, insist that any opposition itemise amounts by nature, by year category and by lot, and test every retained euro against approval, due date and the five-year limitation. The Cour de cassation’s message across the 2017 and 2023 rulings is consistent: the association’s remedies are strong but formal, and a claim that is global, vague or premature will lose its security or its substance. A foreign buyer who masters these four checkpoints — certificate, screening, itemisation, limitation — turns a frightening arrears claim into an ordinary conveyancing step. Readers wishing to understand how these disputes fit within broader French property litigation may also consult our Paris real estate litigation practice before taking position in a deadlines-driven file.