What is a smart lock?
A smart lock lets you lock and unlock your door with a phone app, key fob, PIN code or fingerprint instead of (or as well as) a key. Many also send alerts and keep an activity log. In the UK there are three broad types, and which one suits you depends mostly on your door.
How UK doors differ
UK front doors don’t look like the doors most smart locks were first designed for. You’ll usually find one of these:
- uPVC or composite door with a multipoint lock. MoneySupermarket describes these as having three, four or five locking points that lock together when you turn the key. They are operated by a euro cylinder, which can be vulnerable to lock snapping unless it’s an anti-snap design.
- Timber door with a mortice deadlock and nightlatch. The AA says a five-lever mortice deadlock meets BS 3621, shown by the British Standard Kitemark. MoneySupermarket notes that insurers don’t generally treat a nightlatch as secure enough on its own.
On most multipoint doors you lift the handle to throw the bolts, then turn the key. Tech Advisor’s 2023 review of a smart multipoint lock pointed out the catch: someone still has to lift the handle, so the door can’t be fully locked remotely if it was left with the handle down.
Types of smart lock
1. Retrofit smart locks (fit over your existing cylinder)
These clamp onto the inside of the door and turn your existing cylinder or thumbturn with a motor. The outside of the door doesn’t change and you keep your keys. Examples Which? featured in April 2026 include the Yale Linus L2, Aqara U200 and Bold SX-65. Which? says the Bold SX-65 fits euro cylinders measuring 56–65mm inside and 50–65mm outside.
Fit isn’t guaranteed. Which? says the Linus L2 isn’t compatible with lift-to-lock doors, and when Which? tried a Nuki retrofit lock in 2020, three of its staff couldn’t install it on their doors. Check the manufacturer’s compatibility details before you buy – Yale, for example, has an online compatibility checker. Nuki’s newer Pro model (launched March 2025) also fits over an existing cylinder.
2. Smart cylinders and replacement locks
These replace your cylinder, or your cylinder and handles, with a new unit. The advantage is that you can get a high-security cylinder in the same job. Ultion’s Nuki models come with a 3 Star Plus cylinder, and retailer Lockshop Warehouse lists the cylinder as Sold Secure Diamond and 3 Star Kitemarked. Which? says the Ultion Nuki fits doors with 215mm, 211mm and 122mm handle fixings and needs no drilling or wiring.
Handle-replacement smart locks are built for multipoint doors. Screwfix lists the Yale Conexis L2 as compatible with most UK lift-to-lock multipoint locks with a 92mm centre, on timber, uPVC, aluminium and composite doors 44–70mm thick.
3. Keypad and fingerprint locks
These add a PIN pad, fingerprint reader or RFID tag reader so you don’t need a phone. Some keypad models replace a nightlatch rather than a multipoint lock – for example, Yale says its Keyless Connected fits most 60mm backset nightlatches. Fingerprint options include the Aqara U200 and a Xiaomi self-install lock, and some retrofit brands sell fingerprint keypads as add-ons.
How much does a smart lock cost in the UK?
Which? said in April 2026 that you might spend £200–£300 on a smart lock, against £90–£170 for a standard front door lock replacement. MyBuilder’s August 2026 guide gives these device price ranges:
| Type | Typical device cost |
|---|---|
| Basic smart lock | £100–£150 |
| Keypad | £100–£250 |
| Bluetooth | £120–£280 |
| Fingerprint | £150–£300 |
| Advanced smart lock | £150–£300 |
| Wi-Fi enabled | £200–£400 |
Source: MyBuilder smart lock cost guide, updated August 2026.
Retail prices vary a lot between shops and sale periods. A sample checked October 2026 (in alphabetical order, not a ranking):
| Model | Type | Price seen | Where |
|---|---|---|---|
| Aqara U200 | Retrofit with fingerprint | £149.99 | PriceSpy |
| Ultion Nuki Go | Smart lock with 3 Star Plus cylinder | £189 | Ultion |
| Xiaomi Smart Door Lock Self-Install | Fingerprint | £94.99 | PriceSpy |
| Yale Conexis L2 | Multipoint handle replacement | £163.99–£289.99 | PriceSpy, John Lewis, Screwfix |
| Yale Keyless Connected | Keypad (nightlatch) | £65.99–£71.50 | PriceSpy, Yale |
| Yale Linus L2 | Retrofit over euro cylinder | £142.99 | Yale (sale) |
Source: retailer and manufacturer pages, checked October 2026. Prices change often.
Watch for extras. Trade2Base puts a Wi-Fi bridge at £40–£90 and a keypad or fingerprint reader at £50–£120 where they aren’t included. MyBuilder lists app subscriptions at £3–£10 a month for some products, so check what works without one.
Compare smart lock types, door compatibility and cylinder ratings before you buy, and check the manufacturer’s compatibility details for your door.
Shop Yale smart locksCoverMap may earn a commission if you buy through this link. It doesn’t affect the price you pay.
Security standards explained
- TS 007 (1-star to 3-star). A Kitemark scheme for cylinders and security handles, developed with Secured by Design, the Door & Hardware Federation and the Glass & Glazing Federation. It covers five types of cylinder attack. You reach 3 stars with a 3-star cylinder, or a 1-star cylinder plus a 2-star armoured handle.
- Sold Secure Diamond (SS312). The top grade of the Sold Secure cylinder test, available only for euro cylinders. The MLA says it is treated as equivalent to a 3-star Kitemark cylinder for building regulations.
- BS 3621. The British Standard for thief-resistant lock assemblies, mainly mortice deadlocks and nightlatches on timber doors. Locksmith firm Lock & Key says it isn’t the right label for uPVC, composite, multipoint or euro cylinder doors, where cylinder rating and handle protection matter instead.
- PAS 24. A BSI specification testing whole doors and windows against an opportunist burglar. Door maker Everest says new-build homes have needed it under Approved Document Q since October 2015; the current version is PAS 24:2022.
Smart locks and home insurance
Insurers care about the lock that physically holds the door shut. The AA says most insurers expect locks to at least BS 3621, and that missing them could invalidate cover. MoneySupermarket’s September 2026 guide says insurers may refuse a claim if your door lock doesn’t meet certain standards.
Many smart locks don’t carry a BS 3621 rating. A lock retailer’s 2024 guide says smart locks themselves don’t typically meet BS 3621, but a retrofit lock that turns your existing cylinder doesn’t change that cylinder’s rating. Which? says that as long as a smart lock meets British Standards, fitting one shouldn’t void your cover – but if it’s hacked or a password is stolen, that could affect your ability to claim.
Policies also usually require locks to be used. In a 2025 Financial Ombudsman decision, an Aviva condition that all security protection must be in “full and effective operation at all times” was upheld after a door was left unlocked. Tell your insurer about any lock change and read the security condition in your policy. Our guide to home security insurance discounts covers what else insurers look at, and home insurance costs explains how premiums are set.
Are smart locks safe? The risks to weigh
Flat batteries and emergency access
Which? says smart lock batteries typically last from six months to a couple of years. Several of the models above, including the Yale Keyless Connected, Yale Conexis L2 and Ultion Nuki Go, give a low-battery warning. Check how you get in if the battery dies: some keep a physical key, some come with spare keys, and some rely on a manual override. Keep keys somewhere you can reach from outside.
Wi-Fi and Bluetooth connectivity
Bluetooth has a short range, so remote control needs Wi-Fi – either built in, through a separate bridge, or via a smart home hub for Z-Wave models. If your Wi-Fi or the maker’s app goes down, you may lose remote features, so a backup way in matters.
Hacking concerns and the PSTI law
Since 29 April 2024, the Product Security and Telecommunications Infrastructure (PSTI) regime has applied to connected consumer products sold in the UK, according to GOV.UK. Manufacturers, importers and distributors must:
- not use universal default or easily guessed passwords;
- publish how to report security issues;
- publish the minimum period the product will get security updates.
The NCSC says fines can reach £10 million or 4% of global revenue. Before you buy, check the stated security update period. After fitting, the NCSC advises a strong password (three random words), two-step verification and automatic updates. A 2021 Which? investigation found weak default passwords were a key weakness in the smart home devices it tested, though smart locks weren’t among them.
Installing a smart lock: DIY or locksmith?
Most retrofit and smart cylinder locks are designed for DIY. Which? says most models need only a screwdriver, and Lockshop Warehouse lists the Ultion Nuki as a five-minute fit on most UK doors. Replacing handles on a multipoint door is a bigger job.
If you’d rather pay, Trade2Base’s 2026 guide puts labour-only fitting of a lock you supply at £60–£120 on a euro cylinder door, and supply-and-fit at £180–£400. Premium jobs involving motorised locks or new cylinders and handles can run to £250–£500 or more. MyBuilder quotes fitting at £50–£150. When a new cylinder goes in, West Yorkshire Police advised in 2020 measuring correctly so it doesn’t stick out, and using a Master Locksmiths Association-approved locksmith.
A smart lock is one layer. You can add an alarm system or CCTV, and see how app-based systems compare in smart vs traditional alarms.
Frequently Asked Questions
Can you fit a smart lock to a uPVC door?
Usually, if your door has a euro cylinder. Retrofit locks fit over the cylinder on the inside, and handle-replacement models are made for lift-to-lock multipoint doors. Not every model fits every door, so check the manufacturer’s compatibility details first. You still need to lift the handle to throw the multipoint bolts.
How much does a smart lock cost in the UK?
Which? said in April 2026 that you might spend £200–£300. MyBuilder’s August 2026 guide puts devices at £100–£400 depending on type, with professional fitting at £50–£150. Keypad models for nightlatches were on sale for under £75 in October 2026.
Do smart locks meet BS 3621 for home insurance?
Many don’t carry a BS 3621 rating. BS 3621 mainly covers mortice deadlocks and nightlatches on timber doors. For uPVC and composite doors, the cylinder rating (TS 007 3-star or Sold Secure Diamond) matters more. Read your policy’s lock condition and tell your insurer about the change.
Are smart locks safe from hacking?
No connected device is risk-free. Since 29 April 2024, UK law bans universal default passwords on connected products and requires makers to publish how long they will provide security updates. Use a strong password, turn on two-step verification and keep the app and lock updated.
What happens if a smart lock battery dies?
Which? says batteries typically last six months to a couple of years, and many warn you when they are low. Many keep a physical key or manual override, but not all, so check how you’d get in before you buy.
What is the difference between TS 007 and Sold Secure Diamond?
TS 007 is a Kitemark scheme for cylinders and handles rated from 1 to 3 stars. Sold Secure Diamond (SS312) is the top grade of the Sold Secure cylinder test, which the MLA says is treated as equivalent to a 3-star cylinder for building regulations.
Sources
- Which? – Do I need a smart door lock? (Apr 2026)
- GOV.UK – Consumer connectable product security regulations (updated Mar 2025)
- NCSC – Smart devices: new law
- MoneySupermarket – House locks and home insurance (Sep 2026)
- AA – Different types of door locks
- DHF – TS 007 explained
- Master Locksmiths Association – SS312 Diamond (Jun 2026)
- Lock & Key – BS3621 locks explained
- Everest – What is PAS 24?
- Lockshop Warehouse – Smart locks and home insurance (2024)
- Financial Ombudsman – Decision DRN-5303963 (2025)
- MyBuilder – Smart lock cost (Aug 2026)
- Trade2Base – Smart lock installation costs UK 2026
- PriceSpy – Best smart locks (Oct 2026)
- Screwfix – Yale Conexis L2 smart door lock
- Ultion – Ultion Nuki Go
- Tech Advisor – Yale Conexis L2 review (Jan 2023)
- Which? – Nuki smart lock reviewed (Dec 2020)