You returned the apartment keys, the move-out inventory is signed, and yet your landlord is withholding the entire security deposit because... the mailbox key is missing. That seems disproportionate. Legally, it may not be, and that's the problem.
The 30-second answer
All keys given at the start of the lease and listed in the move-in inventory must be returned, including those for the mailbox, a bike storage room, or a cellar. The Court of Cassation has ruled that the landlord is not required to return the security deposit until all keys have been handed back, and dismissed a tenant's argument attempting to shift the blame onto the landlord. But this does not mean the landlord can keep the entire deposit without justification: they may only withhold the actual, documented cost of replacing the lock or cylinder in question, supported by a quote or invoice—not an arbitrary flat amount, and certainly not the entire deposit for a simple mailbox key. Upload your move-in inventory on bail.immo to check whether the deduction applied is proportionate.
What the law says
Article 22 of the law of July 6, 1989 strictly governs deductions from the security deposit: they must be justified by amounts genuinely owed to the landlord, supported by specific documents (invoices, quotes, comparative move-in/move-out inventory). A deduction "because a key is missing," without a specific amount and without a link to actual harm, does not comply with this provision.
Regarding the return of keys itself, the case law of the Court of Cassation, as analyzed by the ANIL, is clear: the landlord does not have to return the security deposit until the keys—all keys listed at move-in, including the mailbox key—have been handed over or their return has been formally documented. In the case commented on, a tenant left the premises without returning all keys and then claimed the deposit and damages; the court of appeal ruled in the tenant's favor, criticizing the landlord for not arranging a joint move-out inspection, but the Court of Cassation overturned that decision: the tenant remains responsible for returning their own keys, regardless of any potential failures by the landlord in organizing the move-out.
Why this can be a problem
The point of friction is almost always the same: the landlord withholds the entire security deposit, while the actual harm—replacing a mailbox lock—rarely costs more than a few dozen euros. Two rules are at play here, and they do not contradict each other: the landlord has the right to suspend the return while the key is missing, but the amount ultimately withheld must remain proportionate to the actual replacement cost, justified by documentation. A security deposit of €800 withheld in full for a mailbox key worth €15 would not withstand serious scrutiny, even if the principle of the deduction itself is valid.
Concrete example. You leave your home, return the keys to the front door and the building entrance, but forget the mailbox key, which is still on your personal keyring. The landlord writes to say they are keeping the deposit "until the missing key is received." That is defensible as long as no amount has yet been returned. However, if they then announce they are withholding €200 "for the key" without a locksmith's quote, you can legitimately contest that specific amount, while sending (or having a replacement made for) the missing key as soon as possible to unlock the rest.
Exceptions. If the mailbox has a standard lock and a duplicate can be made for a few euros at a locksmith, the landlord cannot justify replacing the entire mailbox system of the building at your expense—only the replacement of the relevant cylinder, at the actual rate, is enforceable.
What to do in practice
- Find the missing key if possible, or have a duplicate made at a locksmith and offer it to the landlord immediately.
- Ask in writing (email or letter) for the exact amount withheld and the corresponding supporting document (quote or replacement invoice).
- If the amount withheld clearly exceeds the actual cost, formally demand that the landlord return the difference, citing Article 22 of the 1989 law.
- If there is no response or justification after the formal notice, contact the departmental conciliation commission, which is free, before considering the judicial court.
FAQ
Can the landlord keep the entire deposit indefinitely for a single missing key? No. They can suspend the return while recovering the key or justifying its replacement, but the amount ultimately withheld must correspond to the actual, documented cost, not the entire deposit.
What if I never find the key? Offer to pay directly for the replacement of the relevant lock upon presentation of a quote, rather than letting the landlord set an arbitrary amount.
Is the deadline for returning the deposit (1 or 2 months) suspended while the key is missing? The cited case law leans that way for the portion of the deposit related to the missing keys, but it does not exempt the landlord from promptly returning the part of the deposit not affected by this dispute.
Unsure about a deduction applied to your security deposit? Have your situation checked on bail.immo.
Sources
- Security deposit in a residential lease — Service-Public.fr
- Failure to return keys and refund of the security deposit — ANIL
Legal information
The information presented on this page is provided for informational purposes and is based on the texts and sources available at the time of its publication or last update. Legislation, regulations, and case law may evolve at any time. The results and explanations offered by bail.immo do not constitute legal advice and do not replace the opinion of a lawyer or another qualified legal professional.