Should You Change Locks After Buying a House?

Yes—changing or reconfiguring the locks after buying a house is normally a sensible early security step because receiving a set of keys does not prove that every copy is accounted for. Previous owners, relatives, neighbours, cleaners, carers, agents, contractors and tradespeople may have held keys legitimately. The issue is not suspicion; it is the absence of a reliable key-control record.

The work should be proportionate. You do not necessarily need to replace every complete mechanism. On a sound uPVC or composite door, changing the correctly sized cylinder may invalidate old keys while retaining the multipoint strip. On a timber door, the appropriate lock or external cylinder may need replacement. At the same time, the locksmith should identify weak standards, projection, alignment faults, damaged windows and secondary entrances.

This guide turns “change the front lock” into a completion-day security plan. It covers every key and code, insurance, smart devices, garages, outbuildings, flats, shared access, children and staged upgrades.

Why Handed-Over Keys Are Not a Security Audit

The seller normally provides the keys in their possession, but property transactions do not produce a forensic history of every copy. A key may have been cut years earlier for a trusted neighbour, adult child, pet sitter or builder and simply forgotten. Keys may also be circulating among agents during viewings and contractors completing last-minute work.

Changing the lock does not accuse anyone. It establishes a new access boundary from a known date, in the same way that changing alarm and Wi-Fi credentials establishes new digital control.

When Should the Locks Be Changed?

Arrange the assessment for completion day or as soon afterwards as practical. Do not book work before legal completion unless the owner and conveyancers have authorised access. Once you have possession, prioritise external doors that secure the occupied home.

If the property will stand empty between completion and moving in, early key control is even more important. Coordinate the locksmith with cleaners, movers and contractors so new keys are not immediately distributed without a record.

Completion-Day Security Priorities

Start With a Key and Access Inventory

Place every handed-over item on a table and identify what it operates. Do not assume unlabelled keys are irrelevant. Test only while you control the property and avoid locking yourself out.

• front, back, side, patio and balcony doors;
• garage vehicle and pedestrian doors;
• shed, gate, bin store and outbuilding locks;
• window handles and restrictors;
• key safes, padlocks, safes and post boxes;
• communal entrance keys and fobs;
• alarm fobs, gate remotes and garage transmitters;
• smart-lock accounts, codes and digital keys;
• meter, plant-room or shared-service access; and
• keys for an internal door linking an attached garage to the home.

Change the Front Door—but Do Not Stop There

The back or side door may be more concealed and may use the same old key. Patio, French and garage-linked doors can create alternative routes. Change priorities should follow accessibility and consequence, not which door visitors normally see.

If several doors are keyed alike, one replacement decision may need to cover the whole group. Ask whether a new keyed-alike system would preserve convenience without leaving an old cylinder active.

What “Change the Locks” Can Mean

Ask exactly which physical component will change and confirm that every old key intended to be cancelled will stop operating the relevant entrance.

uPVC and Composite Doors

These commonly use a euro-profile cylinder controlling a multipoint mechanism. If key control is the only issue and the door operates smoothly, a correctly sized cylinder change may be sufficient. The gearbox, strip, handles and keeps can remain when sound.

Use the visit to assess cylinder projection and attack resistance. Current police guidance recommends a TS 007 three-star euro cylinder when changing this lock type; SS 312 Diamond is another established approval. The chosen product still needs correct measurement and compatible furniture.

Timber Front and Back Doors

A timber door may use a mortice deadlock, sashlock, nightlatch or combination. Determine which handed-over key operates which component. A rim cylinder can sometimes be changed independently, while a worn or unsuitable mortice lock may justify complete replacement.

Where relevant, BS 3621 applies to suitable thief-resistant key-operated lock assemblies. Lever count or a generic “British Standard” label is not enough; confirm the exact product and installation.

Patio and French Doors

Check both leaves, inactive-leaf bolts, locks, cylinders, handles, glazing and anti-lift provisions. A key change alone does not correct loose keeps, dropped alignment or failed locking points. Sliding doors may use specialist locks rather than a household euro cylinder.

Ask the seller or agent for every patio-door key and operating instruction, then have unidentified or uncontrolled access corrected.

Garage and Internal Connecting Doors

An attached garage can provide sheltered access to an internal house door. Change external garage keys, erase old remote controls where the system allows and treat the connecting door as a security and fire-safety boundary. Do not compromise its self-closing or fire-resisting features.

Detached garages and sheds may contain bicycles, ladders and tools. Review their door, frame, hinges, padlock and windows as complete assemblies.

Windows and Restrictor Keys

Window keys are easy to overlook. Identify accessible windows, check handles and locks and determine whether one key operates several units. Retain safe emergency escape where required and do not permanently lock a designated escape window without competent advice.

A missing window key may require a handle or lock change, but first identify the system. Do not force a similar-looking key.

Key Safes and Hidden Spares

Search sensible locations without creating damage: meter cupboards, garages, outbuildings and documented key-safe positions. Ask directly whether neighbours, cleaners or carers held a spare. Remove predictable hiding places under pots, mats, bins and ornaments.

Reset a suitable retained key safe and inspect its condition and installation. Replace it if the code cannot be trusted, the mechanism is damaged or its location exposes it unnecessarily.

Smart Locks, Alarms and Connected Access

Physical lock changes do not remove digital users. Obtain ownership control of supported smart locks, alarm apps, video doorbells, gates and garages. Remove the seller’s accounts and invited users, change administrator credentials, enable two-step verification and update firmware.

Factory reset only according to manufacturer instructions and while you retain another secure access route. Confirm the device’s support period and replace unsupported products rather than connecting them unquestioningly to the new network.

Alarm Codes and Monitoring Contacts

Change user and engineer codes through the proper installer or documented process. Update telephone contacts, keyholders, passwords and monitoring instructions. Test the alarm only after telling any monitoring provider and understanding the procedure.

Do not assume the system is abandoned because it was unset at handover. Old fobs or app users may remain active.

Communal Entrances and Flats

You normally cannot change a shared entrance lock unilaterally. Ask the managing agent which keys and fobs have been issued, how lost credentials are cancelled and what responsibility belongs to the leaseholder. Change your flat’s own key control subject to lease and fire-door requirements.

A flat entrance may be a tested fire-resisting doorset. Replacement cylinders, handles and locks must preserve self-closing, latching, smoke seals, certification and safe escape. Obtain required approval.

Leasehold, Shared Ownership and New-Build Homes

Read lease or management provisions before altering common-facing hardware. A new-build door may be under a manufacturer or installer warranty, and unapproved modifications could affect it. That does not mean uncontrolled keys should be ignored; coordinate an approved cylinder or lock solution.

For shared ownership, clarify the housing provider’s access and maintenance responsibilities. Keep written permission with the installation record.

Locks and Home Insurance

Review the policy schedule and security endorsement as soon as cover begins. Insurers may ask different questions for timber doors, multipoint doors and accessible windows. Answer from the installed products, not from what the estate-agent listing implied.

Ask the insurer to clarify uncertain wording in writing. Keep invoices and product details and use every required lock when the home is unattended. No locksmith product is universally accepted by every policy.

Should You Upgrade While Changing Keys?

Often yes, where the current cylinder is basic or projecting, a timber lock lacks the confirmed required standard, handles are loose, keys are poorly controlled or the door has developing faults. Combining access change and security improvement can avoid duplicate labour.

Do not let the opportunity become indiscriminate upselling. Separate three decisions: what must change to cancel old keys, what must be repaired for reliability, and what optional upgrade improves security.

Security Triage by Budget

Keyed-Alike Locks in a New Home

Keying compatible front, back and side locks alike can simplify daily use. One key loss then affects every grouped door, so the household must maintain stronger key discipline. Not every lock type can join the same system.

Ask how future replacements, extra keys and restricted duplication will work. Keep a schedule showing which key opens which entrance without labelling carried keys with the address.

Restricted Keys and Growing Households

A restricted or controlled key system may suit a large family, home business, carer arrangement or property with regular contractors. It can make casual duplication harder and provide a clearer ordering process.

Consider replacement-key availability, proof requirements, patent or support period, cost and emergency supply. Store security cards separately from the keys.

Children, Carers and Safe Internal Exit

Changing locks is an opportunity to check whether everyone can exit safely. Thumbturns can help where occupants should not need a removable key, but glazing and letterplate reach must be assessed. Double-key cylinders may create delays if the key is removed or hidden.

Families must balance child access, vulnerable-person wandering risk, emergency escape and authorised care. Specialist fire, medical or safeguarding advice may be needed; a lock alone cannot resolve every conflict.

Previous Tenants or Occupiers

If the property was rented, used for short lets or occupied by several adults, the number of historic keys may be particularly uncertain. Change external key control promptly and ask the seller for any master-key, restricted-key or communal-access documentation.

Do not confront a former occupier who appears to retain a key. Secure the property and use conveyancing, legal or police routes appropriate to the situation.

Renovation and Contractor Access

If extensive work begins immediately, consider a staged key plan. One option is to install controlled temporary access for authorised contractors and change the final household cylinder when work concludes. The property must remain properly secure throughout.

Record every issued key or code, set return dates and remove access when each contractor finishes. Do not hide a communal key on site.

Empty Property and Insurance Conditions

A home that remains unoccupied after completion may be subject to different insurer notification, inspection, heating or security conditions. Confirm those directly with the insurer. Lock changes establish key control but do not satisfy every empty-property requirement automatically.

Arrange trusted inspections, secure mail and deliveries, avoid obvious signs of vacancy and ensure contractors know how to lock every door correctly. Do not distribute the only new key informally between trades.

Postal Keys, Mail and Identity Security

New owners can receive post addressed to former occupants. Secure the letterbox or communal post box, change its key where control is uncertain and return misdirected mail appropriately. Do not use information in old post to contact or investigate previous residents.

Keep your own documents, spare keys and vehicle keys away from the letterplate and visible windows. If glazing or an aperture allows reach to internal controls, include that physical weakness in the security review.

Household Handover After the Locksmith Leaves

Demonstrate the new operation to every resident. Multipoint doors may require lift, lock and key removal; automatic mechanisms may behave differently; a thumbturn can change the internal routine. Confirm that children and vulnerable occupants understand what they should and should not operate.

Issue keys through the register, place the controlled spare with a trusted authorised person or secure solution and destroy obsolete labels. Rehearse emergency exit without creating an outdoor hiding place.

The Thirty-Day Review

After living in the property for several weeks, repeat the audit at night and in normal weather. You may discover a little-used side door, an intermittent window lock, a camera blind spot or a garage remote that was never cancelled. Check the key register and active smart users again.

Also review how the new hardware feels. Early stiffness, loose furniture or unusual battery drain should be reported while the installation and symptoms are recent. Security is a maintained condition, not a completion-day purchase.

Record the Baseline Condition

Photograph external doors, windows, cylinders, handles and visible markings after work. Record any agreed pre-existing damage, unusual operating sequence and items awaiting later repair. This is useful for maintenance, insurance discussions and future trades without turning the home into a public security inventory.

Store the record privately with invoices and guarantees. Review it after any future repair or access change. Do not upload close photographs of keys, security cards, alarm panels or identifiable access details to open social media. The purpose is to create a reliable household baseline, not advertise the security system.

What a Locksmith Should Inspect

1. Every external entrance and the keys provided.
2. Door material, frame, hinges, glazing and apertures.
3. Lock type, visible markings, cylinder projection and furniture.
4. Open and closed operation, alignment and seal pressure.
5. Internal escape, thumbturn or key arrangement.
6. Garage, outbuilding, window and secondary-door access.
7. Any known policy, lease or fire-door requirement.
8. Options for key control, keyed-alike use and future copies.
9. Urgent repair versus optional upgrade priorities.

What to Ask Before Work Begins

• Which old keys will stop working?
• Which component will be retained and which replaced?
• What exact product and standard or approval is proposed?
• How many keys are supplied?
• How are future copies obtained?
• Does the door require alignment or mechanism repair?
• Is the internal release suitable for occupants and fire safety?
• What is the complete price, including tax and additional keys?
• What parts and workmanship guarantees apply?
• What records will be supplied?

What to Test at Handover

• operate every new key with the door open and closed;
• confirm old keys no longer operate the intended locks;
• test latches, deadbolts, hooks, rollers and handles;
• check that the door does not need lifting, pulling or force;
• verify safe internal exit;
• count keys, cards, fobs and remotes;
• check cylinder projection and furniture tightness;
• record product, standard and guarantee details;
• label stored records, not carried keys, with the door identity; and
• issue access only to authorised people.

Create a New-Home Key Register

Record each key or credential, its door or permission level, unique identifier where available, date issued and person holding it. Do not store the register openly beside the keys. Review it when cleaners, carers, family members or contractors change.

For digital systems, include administrator accounts, recovery email, support end date and reset procedure. Do not write passwords in the same unsecured document.

New-Home Lock Changes in Northampton

KMI Locksmiths provides home-mover lock changes in Northampton, including British Standard and high-security options, uPVC and timber-door work and free on-site security appraisals. Its home-mover service can be tailored to the property rather than treating every entrance as identical.

Before the appointment, collect all handed-over keys, photograph visible lock markings, find the insurance security wording and list smart devices, alarms and outbuildings. That allows the visit to restore key control and produce a prioritised security plan.

Final New-Home Security Checklist

• Have all physical keys, fobs, remotes, codes and accounts been inventoried?
• Do old external-door keys still work anywhere?
• Have front, back, side, patio and garage-linked doors been covered?
• Are windows, sheds, gates and key safes included?
• Have smart users, alarm contacts and Wi-Fi credentials been reset?
• Do locks meet the actual policy and building requirements?
• Have stiffness, frame damage and cylinder projection been corrected?
• Can every authorised occupant exit safely?
• Are new keys and codes issued through a register?
• Are invoices, product details and guarantees stored securely?

Changing locks after buying a house is not about distrusting the previous owner. It is the moment when access stops being historical and becomes controlled by your household.