Lost keys in a rented flat: who pays for new locks?

Lost keys in a rented flat produce a specific kind of dread: the bill arrives with no itemisation, the number feels invented, and nobody wants to argue with the person who controls their deposit. The law in England is clearer than most tenants realise, and it is worth understanding before you either pay a figure you should not or refuse one you should. This piece weighs what a landlord may charge, what "reasonable" actually means in practice, and where the argument usually turns.

What a landlord is allowed to charge

Since the Tenant Fees Act came into force, most charges to tenants in England are banned outright. Replacement keys are one of a very short list of exceptions, what the legislation calls default fees, payable when a tenant has failed to do something the tenancy required.

Shelter's summary of the position is that a landlord may charge for replacement keys or security fobs only where two conditions are met: the charge is reasonable, and the landlord gives the tenant written proof of what the replacement actually cost. Both conditions matter, and the second one is where most disputes are won or lost.

The practical effect is that a landlord cannot pick a round number. They can recover what they spent, evidenced, and not a penny of administrative uplift on top. A charge of "£150 for the inconvenience" is not a default fee; it is a banned fee wearing a hat.

A second condition sits behind those two: the tenancy agreement has to provide for it. If the agreement says nothing about returning keys or about charges for replacements, the basis for the deduction is much weaker, the deposit is the tenant's money, and deductions have to be authorised by something the tenant signed.

Replacing a key versus changing the lock

This is the distinction that decides the size of the bill, and it is worth separating carefully, because landlords and tenants tend to argue past each other on it.

Cutting a replacement key costs a few pounds. If one key of a set is lost and the landlord holds the others, this is ordinarily the proportionate response, and a charge beyond the cost of cutting is hard to justify.

Changing the lock is a different order of expense and is justified by a security risk rather than by the missing metal. The relevant question is whether the lost key could be matched to the property, did it go missing with a wallet containing the address, a parcel locker fob, a letter? If so, the security argument is real and a lock change is proportionate. If a single key vanished in a park with nothing identifying on the ring, it is considerably weaker.

The trade-off is genuine and both sides have a point. A landlord who does not change the lock carries a risk they did not create. A tenant who pays for a new multi-point mechanism because one key fell down a drain is funding an upgrade to someone else's asset. Reasonableness is exactly the test the law applies, and it cuts both ways.

What happens at the end of a tenancy

Keys not returned at check-out are handled through the deposit rather than as a separate bill, and that changes the dynamic in the tenant's favour.

A landlord claiming for a lock change from a deposit has to be able to show the position clearly: that a set was issued, that a set was not returned, and what the replacement cost. Where a tenant disputes the deduction, the protection scheme's adjudicator decides, not the landlord, and adjudicators are consistent about wanting receipts rather than estimates.

Two practical consequences follow. First, count and photograph the keys you hand back, ideally in front of the agent, and get it noted on the check-out report. Second, if a deduction lands with no receipt attached, asking for the invoice is not an aggressive act; it is the exact thing the legislation requires the landlord to produce.

It is also worth noting the geography. This is the position in England. Wales and Scotland regulate tenant charges through their own legislation, and the details differ, so check the rules for your nation rather than assuming the English position applies.

Where the money actually goes

Look at a lock change bill and very little of it is the lock. Most of it is attendance and labour, and out-of-hours attendance costs multiples of the daytime rate, which is why a set of keys lost on a Saturday night is a materially more expensive event than the same set lost on a Tuesday morning. The 2026 UK trade rates are set out in the locksmith bill for lost keys, and they explain why arguing about the price of a cylinder misses the point.

The lesson for a tenant is unglamorous but valuable: if the keys are gone, deal with it in working hours where you safely can, tell the agent immediately rather than after the weekend, and ask for the quote before the work is done rather than the invoice afterwards.

A considered view

If you rent, three things are worth doing and none of them cost anything.

Read the key clause in your tenancy now, not after the event, so you know what you agreed to. Keep the spare somewhere that is not your flat, a relative, a colleague, because a spare inside the property is no spare at all when the door is shut. And record the handover of keys at both ends of the tenancy with a photograph, because the argument at check-out is almost always about how many sets existed rather than about what a locksmith charges.

Then, if you are the kind of tenant who loses keys rather than the kind who does not, consider spending a small amount to make the next loss a non-event. Not because a landlord would be unreasonable, but because the cheapest version of this dispute is the one that never opens.

How Air Tracker helps

Air Tracker addresses the narrow window in which a lost key is still a findable key rather than a chargeable event.

Clipped to the ring using the key ring in the box, it appears in the Find My app on an iPhone and rings at 80–100 dB whenever you ask it to, from anywhere within about 60 metres, enough to cover a flat, a stairwell and the car park below. Further out, the Apple devices of passers-by refresh its last known position on the map, so you learn whether the set is at a friend's flat or genuinely gone before you have to tell the agent anything. Notify When Left Behind warns you as you walk away from the keys, and Lost Mode lets a finder tap the tag to contact you without ever seeing the address, since the location data is encrypted end to end by Apple.

The honest constraints: Apple hardware from iOS 14.5 is essential and an Android phone will not work with it; there is no Ultra Wideband arrow, so a chime and a pin replace a direction; and it is IP67 rated, about ten grams, with a coin cell that lasts a couple of years and changes in seconds.

One box brings two tags and two key rings for less than £15, one for your set, one for the spare you leave with someone else. Have a look.