Loss of keys in locking systems: Your liability as a protective shield
23 Apr 2025
8
Minutes
Katrin Straub
CEO at nextsure
A lost key from a locking system can quickly incur costs of several thousand euros. Learn how your personal liability insurance can protect you from these financial burdens and which steps are important in case of an emergency.
The topic in brief and concise terms
In the event of losing a key to a locking system, costs amounting to several thousand euros can arise; a private liability insurance is essential here.
Liability insurance typically covers costs for third-party private keys (e.g. rental apartment) and often also for work-related keys.
Always immediately report a loss of keys to the owner and your insurance; in case of theft or if assignable, also to the police.
Immediate measures and cost factors when a key is lost
If you've lost a key, prompt action is crucial to minimize potential risks and costs. Report the loss immediately to your landlord or property management. Costs can vary significantly: replacing a single key may cost around 20 euros, while changing a lock could run up to about 100 euros. For a locking system with 20 parties, the total cost can quickly reach 3,100 euros. Prompt reporting is the first step in damage limitation. A private liability insurance can often cover these costs. The precise procedure and cost coverage depend on the circumstances of the loss and your insurance policy.
Liability insurance: When and what is covered?
Personal liability insurance generally steps in when you lose someone else's private keys, such as the key to your rented apartment. This also applies to keys for communal property in multi-family houses. The insurance then covers the costs for replacing locks or even the entire locking system. Many policies also cover the loss of professionally used keys. Check the exact terms of your policy, as some policies have an excess, often around 150 euros. The importance of liability insurance is clearly evident here. It's important to know that the loss of your own keys, for example, for your own house, is usually not covered by personal liability insurance.
Quick Facts: Key Loss and Insurance Coverage
Here are the key points summarising the topic of key loss and liability insurance:
Report the loss of third-party keys immediately to the owner (e.g. landlord) and your insurance company.
Private liability insurance often covers the costs of replacing locks or locking systems when third-party private keys are lost.
The loss of some work-related keys can also be covered; check your policy for details.
Loss of personal keys (e.g. for your own home) is usually not covered by personal liability insurance.
Consequential damages, such as burglaries following key loss, are generally not covered by liability insurance but may be covered by home contents insurance.
The cost of a locksmith can be covered if the owner is locked out due to your key loss.
Some policies typically require a deductible of around 150 euros.
The exact coverage amount, often up to 50,000 euros or more, varies depending on the policy.
This overview helps you stay calm in an emergency and take the right steps.
Practical examples: This is how liability applies in case of key loss
Imagine losing the key to your rented flat in a multi-family house with a central locking system. The cost of replacing all the cylinders and making new keys for all 20 parties can, as mentioned, add up to over €3,000. In such a case, your liability insurance for key loss would cover the costs, provided that the loss of someone else's private keys is included in your policy. Another example: A tradesperson loses the office key entrusted to them. Here too, the private liability insurance of the tradesperson can cover the damage, if keys used for business purposes are insured. The coverage amount can be crucial here, as replacing a locking system in an office building can quickly cost €25,000. The cost of liability insurance often bears no relation to the potential damage sums.
Expert Depth: Legal Aspects and Current Judgments
Legally, the tenant is obligated to handle the keys entrusted to them with care. In the event of loss, the landlord must be informed. Whether the tenant is responsible for the replacement of a locking system depends on several factors: the tenant's fault and the concrete risk of misuse. A ruling from the Munich Regional Court (Case No.: 31 S 12365/19) states that tenants are not necessarily required to bear the full costs. The court may see shared liability with the landlord if the landlord has not informed the tenant about the potentially high costs of losing keys or the type of locking system (expandable or not). Our expert tip: When signing a lease agreement, clarify whether key insurance is desired or recommended by the landlord. The Federal Court of Justice (BGH) has also decided (Case No.: VIII ZR 205/13) that a reimbursable financial loss occurs only when the locking system has actually been replaced. A purely abstract risk is not sufficient. The question of contribution increase after a loss is also relevant. A correct damage report is essential for processing.
Procedure in Case of Damage: A Step-by-Step Guide
If you lose a key to a locking system, taking a structured approach is important. Here is a guide for emergencies:
Stay calm and confirm the loss: Think carefully about where the key could have been lost.
Immediate report: Inform your landlord, property management, or employer (for work-related keys) without delay. This is often a requirement for insurance coverage.
Inform the police (in case of theft or traceability): If the key was stolen or lost along with documents that could link it to your address, inform the police.
Contact insurance: Report the loss to your personal liability insurance. Clarify the cost coverage and further steps.
Damage mitigation: Discuss with the owner (e.g., landlord) what security measures are necessary (e.g., emergency lock).
Documentation: Record all steps, agreements, and costs incurred in writing.
Check your rental agreement: Look to see if your tenancy agreement contains provisions regarding key loss.
Our expert tip: Save the emergency numbers of your insurance and landlord in an easily accessible place. This approach helps to minimise damage and to ease handling with the insurance.
Distinction from Home Contents Insurance and Special Cases
It is important to distinguish between the responsibilities of personal liability insurance and contents insurance. While personal liability insurance covers damage to third-party property (e.g., the landlord’s lock system), contents insurance covers damage to your own possessions. Consequential damage from a key loss, such as a burglary in your home where your property is stolen, typically falls under contents insurance. However, there are limitations: if the key was stolen due to negligence, contents insurers may not pay out (BGH ruling 2023, IV ZR 118/22). Costs for a locksmith for your own door can sometimes be covered by a home and apartment protection policy, which is often part of contents insurance, usually up to an amount of 500 euros. Lost car keys are generally not covered by personal liability or contents insurance; vehicle insurance is responsible here. The question of when exactly liability insurance applies thus depends on the type of key and the situation.
Prevention and additional safeguarding options
Your next step towards optimal protection
More useful links
Finanztip offers comprehensive information on key insurance as part of private liability insurance.
The Bund der Versicherten provides a detailed information sheet on private liability insurance.
Haufe explores in an article who bears the costs when a key is lost in a locking system.
Haus & Grund Deutschland informs about the legal aspects of key loss in tenancies.
The Verbraucherzentrale warns of the high costs that can arise from losing a master key.
Wikipedia offers a comprehensive overview of private liability insurance.
The Mieterverein München explains the tenants' obligations regarding key loss.
The Federal Court of Justice (BGH) provides a ruling here concerning the obligation to reimburse costs in the event of key loss.
FAQ
What is the difference between losing your own key and someone else's key?
Foreign keys are, for example, keys to your rented apartment (the property of the landlord) or keys provided by your employer. The loss of these is often covered by personal liability insurance. Your own keys belong to you (e.g., keys to your own home); their loss is usually not covered by personal liability insurance.
Does the liability insurance also cover consequential damages, such as a break-in following loss of keys?
No, consequential damages such as a break-in are generally not covered by personal liability insurance. The household contents insurance might be responsible for this, but often only if the theft of the key was not negligently facilitated.
Does liability insurance cover the costs for a locksmith?
If you lose someone else's key and the owner needs a locksmith as a result, your liability insurance may cover the costs. For your own door, a home and contents protection policy (often part of your household insurance) might apply.
What happens if I lose the key and there's no risk of misuse?
If there is no specific risk of misuse (e.g. a key falls into a deep lake and cannot be retrieved), the tenant often does not have to pay for the replacement of the entire locking system, even if at fault. However, the cost of a replacement key might be incurred.
What is the excess for key loss in liability insurance?
Some plans include a deductible, often around 150 euros. However, there are also plans without a deductible. To find out more, please review your contract terms.
Is the landlord required to inform me about the costs of a locking system?
Yes, courts have ruled that landlords may have a duty to inform tenants about the potentially high costs of losing keys and the type of locking system in place. Failing to provide this information can result in the landlord sharing some liability.
