Here is a question to the blog clinic from Margaret (not her real name) who is a tenant:
My tenants have not returned one set of keys and claim they lost it. Can I withhold the cost of changing the locks from their deposit?
The answer is probably yes, so long as you can prove you gave the tenants one more set of keys than they returned.
In any claim, you have to consider
- Liability – whether the tenants are liable for the item, and
- Quantum – how much they should pay you
As far as liability is concerned, this an example of why it is important to have a proper inventory at the start of the tenancy – which should state how many sets of keys were provided to the tenants.
Here though, the fact that the tenant says they have lost them makes things easier for you.
The fact that there is another set of keys floating around does compromise the security of the property so you should be justified in charging for the locks to be changed.
As regards quantum, the best thing to do is to produce a receipt for the money paid.
However, it should be for an equivalent type of lock. You cannot use this as an excuse to instal a far more expensive and secure lock and expect your outgoing tenant to pay for it!