How to Handle a Lock Change After Lost Keys Without Losing the Paper Trail

Log the lost-keys report, secure the let the same day, send the itemised locksmith invoice, update the key schedule, and tell the insurer if asked.

18 September 2026•1 min read•Article•IziRento Editorial

Rental operations notes from the IziRento team. Not legal advice.

Key takeaways

A mid-tenancy lock-change file is the written report, same-day secure, and the itemised locksmith invoice. Keep the updated key schedule with a signed receipt, plus an insurer note if the policy asks. Charge only reasonably incurred cost if the tenancy allows a lost-key default, and send that invoice in writing. Issue the new keys the same sitting.

The keys are already on a Hull bus, and the only file is a WhatsApp. Write what was lost, when, and where last seen. Secure the property the same day with the tenant still able to get in. Keep the itemised locksmith invoice that shows actual cost and send it in writing. Issue the new set against an updated key schedule with a signed receipt, then tell the insurer if the policy asks.

Tuesday at Kit’s one let in Hull, the tenant WhatsApps “lost the keys on the bus”. Kit replies “ok I’ll sort it”. A locksmith comes that evening; Kit pays cash; the invoice stays on the locksmith’s phone. Friday Kit texts “that’ll be £150” and the tenant asks for the invoice. There is no itemised receipt, no note of what was lost, when, or where last seen, and no signed receipt for the new set.

The problem is a WhatsApp plus a round number is not the charge file. The risk is Friday: they ask for the invoice and you have none. There is no official UK lost-keys incident form. What the Tenant Fees Act 2019 Schedule 1 paragraph 4 requires is the invoice. Costs reasonably incurred, with evidence in writing given to the person charged. Typical mistake: treating Tuesday’s chat as the whole file.

Disclaimer: IziRento is operations software, not legal advice. Local tenancy rules vary; check a qualified adviser for binding decisions.

How do you log a lost-keys report the same day?

Write what was lost, when, and where last seen, on the same day. Name each key, fob, communal tag, garage key and alarm fob. Note an address tag, ID or bag, and which doors that set opened. A spare restores access, not security. Save the WhatsApp or email as a PDF.

Do write those fields even if they already used a spare. KMI Locksmiths (8 May 2026): it is not simply “lost versus found”. Where the keys went, what was attached, and which doors they open all matter. Cutting another key does not cancel the missing one.

Do file the thread, not a memory of it. Sandra Davidson (1 June 2026): document what was lost, the solution, and any charges, and keep receipts. Do not treat a verbal “lost the keys” as the file. For example, Kit’s WhatsApp could have been the report if those fields were in it.

Written same-day lost-keys report versus a verbal chat, with what, when and where fields

A cash locksmith is not the file

Cash plus a “that’ll be £150” text is not an itemised receipt. Get the PDF that evening, then send it in writing.

What to do the same day so the tenant can still get in?

Secure the property the same day, with the tenant still able to get in. Keep it occupied where it is safe. Lock unaffected doors and windows. Book a locksmith for the affected cylinders — the lock barrels the missing set still opens. Hand the new keys to the tenant the same sitting.

Do write a one-line note of what you locked and when the locksmith is due. Alan Boswell: if keys are lost or stolen and locks are not changed quickly, delay can invalidate landlord insurance because the property is not secure. Stolen keys, keys with ID, or keys lost close to home mean you change the affected locks promptly.

Do not change the locks to keep the tenant out. Issuing the new set the same sitting keeps this a security job. Changing locks while they are out, or denying re-entry, is an offence under the Protection from Eviction Act 1977 section 1. Do not hide the new keys or delay the hand-over.

Communal street-door keys are a fork. Change or rekey the flat door you control. For a communal key, tell the managing agent or freeholder the same day. Deacon (20 February 2025): a locksmith will not open the shared street door on one resident’s say-so. Charge only the evidenced communal cost that lands on you.

Same-day secure flow: lock unaffected doors, book the locksmith, hand new keys over

Which invoice can you actually show for the charge?

The charge file is the itemised locksmith invoice or receipt, in writing, showing actual like-for-like cost. The tenancy must already allow a default fee — a charge the agreement permits after a specified default — for a lost key or security device. The tenant does not have to pay until that evidence arrives.

Do file that invoice and send it the same day you have it. GOV.UK fees you can charge (updated 7 July 2026, England): a lost-key default fee is allowed if it is in the tenancy. Evidence in writing must show the costs are reasonable. Shelter (updated 1 May 2026): reasonable, with written proof of replacement cost.

The tenant-guidance PDF is blunt. The tenant does not have to pay until they have received this evidence. That evidence is an itemised invoice or receipt. A flat extra £100 as well as the replacement is not likely to be permitted.

In practice, an invoice that shows the loss is what holds. A mydeposits case awarded £90 in full because the invoice showed the loss. Do not add a round admin on top. Do not upgrade the cylinder and bill the extra.

Checklist for an itemised locksmith invoice showing like-for-like cost in writing

How do you update the key schedule after the cylinder changes?

Patch the existing key schedule — who holds which keys — rather than a new day-one count. Void the lost lines. Add the new cylinder identity and key count. Who received which set, dated. Get a signed receipt the day they take the new keys, or a same-day email listing each line.

Do write the new lock identity on the same sheet you already keep. Alan Boswell: know who has which keys and how many sets are in circulation. How to file keys and fobs at handover owns the start-of-tenancy count. This incident only updates that schedule after the cylinder changes.

Do file a signed receipt, or the same-day email if they will not sign. Do not leave the new keys with a neighbour “until they get back”. Do not keep a landlord spare off the schedule.

When to tell the insurer about lost keys?

Read the policy before you assume cover. Some wordings pay for loss of keys, some only for theft and want a crime number. Send the date, what was lost, and the locksmith invoice. Typical published examples start around £500 and vary.

Do set a one-line note of what you sent and when. Alan Boswell: typical lock-replacement limits start at £500 and vary. Vasek Tenanted Property Essential wording (May 2026) lists replacement locks after theft or loss of keys, with an example limit of £500. That is one live wording, not a UK standard. Some policies cover theft, not loss — keep a crime number if that is the wording.

Do not send an occupancy-empty disclosure as a substitute. How to notify the insurer when occupancy changes owns the empty / let-again email. The locksmith invoice can also sit in the contractor invoices and job-sheets folder as a paid-work clip.

Do file the clip on this let. Success bar: Friday opens one card. On it: report, same-day secure note, itemised invoice sent, updated key schedule with a signed receipt, insurer line if asked. Verify that checklist, then stop. Workflow: report → same-day secure → invoice → updated schedule → insurer if asked. An IziRento workspace can hold those records on this lease.

Lock-change incident file on this tenancy

Log the report in writing the same day
What was lost, when, where last seen, and which doors that set opened. Save the WhatsApp as a PDF.
Secure the property the same day
Keep it occupied where safe. Book a locksmith for affected cylinders, or tell the managing agent if a communal key is on the ring. Hand the new keys over the same sitting.
Keep the itemised locksmith invoice
Charge only the like-for-like figure if the tenancy allows a lost-key default. Send the invoice in writing. No £100 admin. No charge for your time.
Issue the new set against an updated key schedule
Void the lost lines. Add the new lock identity and key count. Signed receipt, or a same-day email listing each line.
Tell the insurer if the policy asks
Read whether cover is loss or theft-only. Send the date, what was lost, and the invoice.
If the keys appear, write the find on the same report
A bus gap still usually means the affected locks change. Do not bill work that was not done. File the clip on this tenancy.

FAQ

What evidence do I show the tenant for the charge?

The itemised locksmith invoice or receipt, in writing, showing actual like-for-like cost. They do not have to pay until they have it, and the tenancy must already permit the default fee.

Do I change communal and flat locks?

Change or rekey the flat door you control. For a communal key or suited fob, tell the managing agent the same day and charge only evidenced cost that lands on you.

What if they found the keys the next morning?

Record the find on the same report. A found key is not a cancelled copy if they were out of control on a bus.

Who pays if we upgrade the cylinder?

The tenant pays like-for-like restoration after their loss. Upgrade extra sits with you; a worn lock with no loss is your repair.

What if the tenant already called a locksmith?

Take their itemised invoice, check it is like-for-like, update the key schedule, and issue your spare the same sitting.

Does this apply in Wales or Scotland?

This card is England. Wales and Scotland use different fee rules.