Retrofit door lock monitor
Know if your door is locked anytime, anywhere.
Locksure fits beside the thumb turn or key you already have and tells your phone whether the door is locked.
No drilling, no new lock, no subscription.
Works with the Locksure app and display hub · Alexa
Using Apple Home, Google Home or Home Assistant? See the Matter range
of burglaries happen through unlocked doors
Know your door is locked, anytime, anywhere. Your insurance-rated lock stays exactly as it is.
Source: Office for National Statistics.01 / Your door
Which way do you lock it?
Choose by the inside of your door. Every starter pack includes the Locksure display hub and app, and keeps your existing lock and keys.
Only monitors lock state. Cannot lock or unlock your door. Unsure about fit? Check your door or ask us before ordering.
Already have a Locksure hub? Add another door
Thumb Turn Additional Monitor Pack
One more Thumb Turn monitor for another door. Needs a Locksure hub; 10% off with a starter pack.
£49.99
Key Turn Additional Monitor Pack
Inside and outside Key Turn monitors for another door. Needs a Locksure hub; 10% off with a starter pack.
£69.99
Full details: Thumb Turn Starter Pack · Key Turn Starter Pack
The Matter range
Use Apple Home, Google Home or Home Assistant?
The Locksure Matter monitors report straight into your smart home, with no Locksure hub needed. They need a Matter controller and a Thread border router.
Shop the Matter Monitors →02 / How it works
Fitted in minutes. No drilling.
No new door. No lock swap. No subscription. Locksure works with the lock you already have.
Stick the monitor
It fits beside your thumb turn or key turn with the supplied adhesive. Your insurance-rated lock stays exactly as it is.
Plug in the hub
Put the Locksure display hub near your doors and connect it to your Wi-Fi with the Locksure app.
Check anywhere
See locked or unlocked on the hub, in the app or by asking Alexa, and look back at when it changed.
The monitor flashes cyan for locked and amber for unlocked. The lights do not stay on continuously.
03 / The answer on your phone
Every door, at a glance.
The Locksure app shows each door as locked or unlocked, and keeps a history of when it changed.
Away from home, in bed or already in the car: open the app and the answer is there. Prefer to ask? Alexa can tell you too.
Genuine Locksure app screenshot with example door names. Free app, no subscription.
04 / Included in every starter pack
The display hub comes in the box.
Every Thumb Turn and Key Turn starter pack includes the Locksure display hub. It connects your monitors to Wi-Fi, the Locksure app and Alexa, so there is nothing else to buy.
Round display
One glance. Up to four doors.
Before bed or on your way out, check your doors together on the hub's round display, without reaching for your phone. Each door shows by name with its lock state.
One hub covers up to 4 nearby doors. Place it near a power socket between the doors it monitors.
See Locksure in action
30 seconds, with sound.
05 / Monitor or smart lock?
Locksure compared with a smart lock
A smart lock replaces your lock. Locksure keeps it and tells you whether it is locked.
| Feature | Locksure monitor | Smart lock |
|---|---|---|
| Install | Keep your lock, no drilling | Often requires replacement and install |
| Control | Monitors status (no remote unlock) | Remote lock and unlock |
| Security risk | No hacking risk from remote control | Electronic tampering possible |
| Battery | 1.5 years | 3 to 4 months |
| Typical price | £89.99 (hub included) | £200 to £500 including hub and fitting |
Smart lock figures are typical ranges, not a specific product. See how Locksure compares → · Smart lock vs lock monitor
06 / More than one door
Multiple Doors? Here’s How It Works
Each hub monitors up to 4 nearby doors. If doors are in different parts of the house, simply add another hub.
Place hubs centrally
Position each hub between the doors it monitors. A hallway shelf near a power socket works perfectly.
Up to 4 doors per hub
Each hub monitors up to 4 nearby doors. For most homes, 1 or 2 hubs cover every entrance.
One app, all doors
Every hub appears in one app. Check all your doors at a glance, with no switching between devices.
07 / Check before you buy
Will it fit my door?
If you have a thumb-turn or Euro cylinder key-turn, you're good. Locksure is designed for suitable euro-cylinder installations.
Not sure what you have?
Send us a clear photo of your lock, including the handle, cylinder and the space below it, and we will check it before you order.
Ask us to check my door ↗Renting? Check that you have permission to attach the monitor.
Check for a flat lock plate and at least 34 mm of flat space below the cylinder. The cylinder must stick out at least 1 mm: lay a coin across it, and if it sits flush, it will not fit.
Returns are free within 30 days.
08 / Who it is for
Stay Connected to What Matters Most
Locksure's Connected Family Safety isn't just about locking doors. It brings families closer together through shared peace of mind.
- Share doors with other family members
- Activity history shows when doors were locked or unlocked
- Private and secure: your family data stays within your circle
- Perfect for multi-generational households
Supporting Elderly Parents
Install the device in your parents' home and have them share it with you. Check their door and gently remind them if it was forgotten, giving them independence and natural opportunities to check in.
Peace of Mind for Working Parents
See that the door was locked after the school run, and know the house is secured without constant texting.
No More Turning Back
Already on the road and wondering "did I lock the door?" Simply check the app for peace of mind, with no need to turn the car around.of burglaries happen through unlocked doors. Know your door is locked, anytime, anywhere. Your insurance-rated lock stays exactly as it is. Source: Office for National Statistics.
09 / Always improving
What's in the pipeline?
We're always working to make Locksure better. Here's what's coming.
Voice Assistants
Already works with Alexa: just ask "Is my front door locked?" More voice assistants coming soon.
Alexa: live now
Smart Home Dashboards
View your lock status alongside your other smart home devices. Compatible with popular home automation platforms.
Live now via Matter
Automations
Connect Locksure to hundreds of apps and services. Get alerts, flash your lights, trigger routines, and more.
Live now via Matter
10 / Customer reviews
What Our Customers Say
The visual flash of the LEDs alone when I lock the door really stick in my memory. Locksure has been on my door for over six months now and I want to keep it!
I was skeptical at first because I don't have the problem of forgetting to lock my doors. Well I didn't think I did until I realised how long the door is left open by my kids! The history feature really help me get to the truth of when the kids came in and out of the house, even when I am in the office!
The kids can make getting into the car a stressful experience sometimes. Then I get onto the A1 and think "have I locked the door?" Now I just stop and look at the app and I know for sure! Thanks Locksure!
We have a three story house and, just before bed, I get paranoid if I remembered to lock the door and end up going all the way downstairs to check. No more with Locksure, I just check the app and have peace of mind.
I rent a flat and can't change the lock, so this was the perfect solution. It sits neatly over the existing key turn and connects easily to the hub. I love that I can see if the door is locked from anywhere using the app. No security risks like remote unlocking, just simple status updates.
Very easy to set up and install too. Super simple in fact. Well packaged and everything is clearly labelled. Works well. Well made, wonderfully packaged and the company seems to offer good after sales support too. Would recommend.
11 / Good questions
Questions, answered
Will it fit my door?
If you have a thumb-turn or Euro cylinder key-turn, you're good. Check for a flat mounting surface and at least 34 mm of flat space below the cylinder. Unsure? Send us a photo and we will check it before you order.
Do I need to change my lock?
No. Locksure is a retrofit sensor - it reads the lock position; it doesn't operate the lock.
Can I lock or unlock the door with my phone?
No. Locksure has no motor. You operate your existing key or thumb turn; Locksure monitors and reports the state.
Does it work if my Wi-Fi goes down?
The hub keeps state; cloud/app updates when your hub is back online. Your lock and keys work exactly as before.
How many doors does one hub cover?
Each hub monitors up to 4 nearby doors. If doors are in different parts of the house, add another hub. Additional monitor packs are 10% off with a starter pack.
How long does the battery last?
Each monitor runs on a replaceable CR2032 coin cell, typically 18 months depending on use.
Is there a subscription?
No. There is no subscription for lock-state monitoring.
What's your returns policy?
30-day free returns and a 1-year warranty from our UK team. For any questions or installation issues please email [email protected].
12 / Guides
Learn before you lock up
13 / Our story
A Family Driven Solution
Born out of a real-life necessity, our journey began when we recognised the vulnerability of homes, particularly those of elderly residents, to opportunistic thieves. Our founder's own father-in-law often forgot to lock his front door in a neighbourhood targeted by such criminals.
A smart lock seemed plausible, but the cost, including installation and an additional hub, made it an impractical way to simply know if the door is locked, and remote control over the locking mechanism seemed less secure. So we built a door lock monitor that reports the lock state and leaves the lock alone.
After it worked in our own home, neighbours asked how it could help them remember to lock their doors too. We tested Locksure with our friendly testers and now design, make and support it in the UK.
Your lock, with an answer
Know if your door is locked.
Anytime, anywhere.
Choose the starter pack for your door, or the Matter range for your smart home.
Locksmith or alarm installer? For Locksmiths → · For Alarm Installers →
Ask Locksure
Got a question?
Ask about fitting, which monitor suits your door, ecosystems or delivery. We reply by email. For a fit check, attach a clear photo of your lock and surrounding space.
Europe launch
Outside the UK?
Locksure is coming to Europe. Leave your email and we will tell you when it launches where you are.
This signup is separate from asking a product question.