The best additional door locks, compared.
Top pick: hzuisst French door handle lock – Highest score: 4.7 from 444 reviews and 50 UK review headers, for two horizontal levers at about £19.99. It works only while it is on the handles. Best value: Sandiyago sash jammer, 4 pack – About £8.99 and 4.5 from 1,338 reviews for a non-locking jammer. Short screws and shearing spacers are already deducted. Updated October 2026.
An additional door lock is a second fastening, not a new euro cylinder or a multipoint lock. On amazon.co.uk the phrase covers sash jammers, a handle clamp, reinforcement bolts, a portable brace, loop latches, cabin hooks and a child lever lock. A non-locking jammer or a brace only works while someone is in to set it. The main lock still has to meet BS 3621 on a timber final exit, or a multipoint with an anti-snap cylinder on uPVC. The ranking uses amazon.co.uk stars, the UK review headers behind them, and whether the product does one extra-lock job. Hollow frames and outward leaves are covered for [uPVC and composite doors](/hub/door-and-window-security/additional-door-lock/sub/additional-door-lock-upvc). Extra resistance while you are in is a non-locking sash jammer or a handle clamp.
An additional door lock is a second fastening, not a new euro cylinder or a multipoint lock.
42 products checked · 64 hrs invested · +24,100 readers
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Personal buying guide
Question 1 of 2
When does it need to work?
The hzuisst WH-KN6168-2 is a white clamp, 34 cm long and 720 g, that you push onto two horizontal levers, listed at about £19.99 and rated 4.7 from 444 reviews. Fifty review headers are marked United Kingdom. Reviewers fit it to white uPVC French, patio and conservatory doors in about a minute, and some left it on when the main lock had failed. It comes off with a push button, so it only works while it is sitting on the handles. The listing excludes vertical and curved handles. People who like the look still say they do not know how it would do in a real burglary. It does not replace the multipoint lock or an anti-snap cylinder.
Pros
Cons
Best for: You have two horizontal levers on French, patio or conservatory doors and you want a clamp you can fit without a drill while you are in.
Less suitable: Vertical or curved handles, an empty house, or a door whose multipoint lock has failed for good.
Specifications
Common questions
Can this be used on uPVC French doors?
UK reviews fit it to white uPVC French and patio doors. The listing says horizontal handles only, not vertical or curved ones.
Does it come with a key?
The listing lock type is a push button. No key is named in the spec.
The Anobeyi AI-Loop Lock02 is a white aluminium U-loop at about £6.99, rated 4.7 from 107 reviews. Only one review header is marked United Kingdom, and that note says it is smaller than expected and still does the job. Other reviews describe about 15 minutes to fit, a barn-style bathroom door, and a screen door held in wind. A narrow patio frame would not take it flush. One pack had corroded screws, and several people replaced the supplied screws with longer ones. You drop the bar to latch it and lift it to open it. The listing says both 360 degrees and 90 or 180 degrees, and does not settle which mount is right. It is an auxiliary latch, not a keyed deadlock.
Pros
Cons
Best for: You have a wide enough frame on a sliding, barn or screen door and you want a drop-bar latch.
Less suitable: A narrow patio frame, a euro-cylinder uPVC door, or a decision based on UK reviews.
Specifications
Common questions
Is it for outdoor use?
The listing says indoor and outdoor doors, windows and gates. Almost all written reviews are from outside the UK.
How is it fixed?
Screws. A review says one leaf goes on the frame and one on the door, and that a narrow patio frame will not take it.
The ZHENGZHOU HP t-02 is one 200 mm stainless cabin hook at about £4.99, rated 4.6 from 352 reviews, with 50 UK review headers. Reviewers use the 8 inch reach to hold PVC French doors open on a brick wall, and to fasten a shed door or a gate. Several say it has not rusted outside, and that the screws and wall plugs sit in a small footprint. One outdoor fit did rust. The same UK comments mostly describe holding a door ajar rather than locking a house overnight. If you leave the hook off the eye, the door is as it was. It is not a keyed extra lock.
Pros
Cons
Best for: You want a long hook to hold a shed, gate or French door open, or a light latch you set by hand.
Less suitable: You want an extra lock on a front door while you are out.
Specifications
Common questions
Can this hook be used on a shed?
The listing names a shed door, and a UK review used it to secure a shed door. Other reviews use it to hold French doors open.
Does it include fixings?
Yes. The listing includes the cabin hook, original screws, spare screws and wall plugs for brick or concrete.
Across 1,338 amazon.co.uk reviews at 4.5 stars, the Sandiyago four-pack is the sash jammer people fit to uPVC, wood and composite, listed at about £8.99 and ranked 4 in Window Locks & Latches. Fifty review headers are marked United Kingdom. Fitters often use two screws per arm. Some used the set as a temporary hold when a uPVC back-door lock had failed, and one used it to stop a dog turning a thumb-turn. The complaint that repeats is the screws, about 30 mm, which were too short for some doors, and spacers that sheared instead of clipping. Arm stiffness also varies inside one pack, and two of four arms were too stiff for a main exit in one review. There is no key, so the door is only blocked while you are in to twist the arm.
Pros
Cons
Best for: You want a non-locking jammer on a hinged uPVC, wood or composite door while someone is home to set it.
Less suitable: You need the door secured after you leave, or screws long enough for a thick frame without buying more.
Specifications
Common questions
Will these fit wooden windows?
The listing says PVC-u and wood or composite doors and windows, including vertical sliding vinyl windows.
Are the supplied screws long enough?
Reviews say the screws are about 30 mm and were too short for some doors. Spacers in the pack also failed to clip for some fitters.
This black 75 mm pair from Zhengzhou HP is rated 4.5 from 1,262 reviews, with 50 UK review headers, and listed at about £6.09. Buyers fit both hooks in about 10 minutes and use them to hold shed doors and gates open in wind, or to latch a catio from the inside. The listing asks you to mount the hook on a slope of about 30 degrees so it does not jump the eye. One reviewer still had a dog push the gate after the hook slipped, and another replaced the 3.5 x 16 mm screws with longer ones. The black epoxy is described as outdoor coating, and several reviews report no rust so far. It is a holder and a light latch, not a lock you can leave on a house door.
Pros
Cons
Best for: You want a pair of short hooks to hold a gate or shed door, or a light indoor latch.
Less suitable: You want a lock that resists a push, or a fastening for an empty house.
Specifications
Common questions
Can these hooks be used outdoors?
The listing says the black epoxy coating is for outdoor use. UK reviews mostly hold shed doors and gates open, and several report no rust so far.
Are screws included?
Yes. Eight 3.5 x 16 mm screws, eight spare 3.5 x 25 mm screws and four 5 x 25 mm wall plugs.
The Moonybaby two-pack is an adhesive ABS blocker for lever handles, listed at about £7.99 and rated 4.5 from 1,250 reviews. It is ranked 1 in Door Locks & Window Guards inside Baby Products, not in a security aisle. Parents stick it at the top of the stairs or on a bathroom and press two buttons together to release it. Reviewers say the pad holds once it has set. A toddler pulled a fresh one off on day one in one review. Adults find the two-button release awkward one-handed, the lock sits under the handle, and taking it off leaves marks. It does not lock the door when the house is empty. Check the handle shape before you stick it.
Pros
Cons
Best for: You want to block a lever a toddler can reach, at the top of the stairs or on a bathroom, without drilling.
Less suitable: You want burglary resistance, a round knob, or a lock that stays on when you go out.
Specifications
Common questions
Does this fit every door handle?
The listing tells you to check the handle first. It sticks on with tape and blocks the lever. It is not a keyed lock.
Do adults need a key?
No. Adults press two buttons together. Reviews say that is awkward one-handed, and that a toddler can pull a fresh one off.
The Annakideya FDMK-W-1 is a white aluminium slide bolt at about £12.99, rated 4.5 from 85 reviews, with 16 UK review headers. The listing calls it 3 inch and also 35 mm, so measure the edge before you drill. You screw it to the inside of the door and the frame, and it can stay slid shut when you are out, which the jammers in this set cannot do. Reviewers use it at night and to stop children opening a front door. The supplied screws stripped for one fitter, who switched to their own. One review says the thin frame plate bent during a burglary. The 800 lb figure is the listing, not a test cited with it. Unlocking is a pinch and a slide, not a key, even though a field says key unlock.
Pros
Cons
Best for: You can drill a timber edge you control and you want a bolt that stays across when you are out.
Less suitable: A hollow uPVC frame, or anyone expecting the 800 lb line to be an independent test.
Specifications
Common questions
Do you need a drill?
The listing says a drill and screwdriver may be required. Reviews report stripped supplied screws.
Is the 800 lb figure a UK test?
It is printed on the listing. One review says the thin frame plate bent during a burglary. No separate test report is cited with the listing.
Across 2,799 amazon.co.uk reviews at 4.4 stars, the DoorJammer DJ3 is a 210 g red steel brace for inward-opening doors, listed at about £22.72. Fifty review headers are marked United Kingdom. Travellers use it in hotels and Travelodges, and it comes off with an upward release. The listing needs at least 3 mm of gap on a flat floor. One buyer found that minimum still too tight and suggests about 5 mm. Reviews say it skews as you tighten it and is less stable on carpet, and one booklet did not match the product. The maker’s FAQ says most uPVC doors are unsuitable, and a PAS 24 line on the device is not a PAS 24 door. It does nothing once you leave the room and take it with you.
Pros
Cons
Best for: You travel, or you rent, and the door opens inward with a clear gap of at least 3 mm on a flat floor.
Less suitable: An outward uPVC door, a thick weather bar, carpet you cannot trust, or a house you leave empty.
Specifications
Common questions
Can you use it on carpet?
The listing says carpet, tile and laminate if the floor is flat. UK reviews say it is less stable on carpet.
Does it work on every door?
No. The listing limits it to inward-opening doors with at least 3 mm clearance. One review found the minimum gap still too tight.
The MeBantoo UKFY-Loop Lock 02 is a white loop latch at about £6.99, with a bar listed at 60 mm by 100 mm, rated 4.4 from 64 reviews. Only one review header is marked United Kingdom. The title says stainless steel and the material field says aluminium, so the metal is not settled. A lock-type field says pin tumbler, while the bullets describe a bar you lift and drop. Non-UK reviews say it holds a screen door in wind and copes with a sagging gate better than a barrel bolt, and that it looks lighter than the photo. A reviewer calls it a latch rather than a lock, and light for an exterior fence gate. Anyone who can reach the bar can lift it, including a child.
Pros
Cons
Best for: You want a small drop-bar for a screen, a cupboard or a light gate, and you can check the metal in the box.
Less suitable: A heavy exterior gate, a keyed lock, or a listing you need to trust on material.
Specifications
Common questions
Can it go on a garden gate?
The listing says garden gates. A review says it feels light for an exterior fence gate and is easy to open.
Is it stainless steel?
The title says stainless steel. The material field says aluminium. The listing does not resolve that.
Across 41 amazon.co.uk ratings at 4.4 stars, this zgpzlhd six-pack is a set of white cast-zinc sash jammers for PVC and uPVC doors and windows, listed at about £7.99. Twelve of the review headers are marked United Kingdom. People who fitted them say the arms feel solid once on and stop a house door or a French door from opening. The pack is listed at 300 g and includes six screws and six caps. There is no key. One reviewer said a door took longer to fit than expected, and another found scratches and black marks because the jammers arrived in a plastic bag with no wrap. The arm only blocks the sash while someone is there to swing it across.
Pros
Cons
Best for: You want several non-locking jammers for uPVC doors and windows you can set while you are in.
Less suitable: You need a keyed lock that stays on when the house is empty, or a large UK review sample.
Specifications
Common questions
Can these sash jammers be used on uPVC doors?
The listing says they are for PVC and uPVC windows and doors. You twist the arm to block the sash. They are not described as keyed.
What is in the pack?
Six sash jammers, six fixing screws and six knock-on cover caps. The listed pack weight is 300 g.
The PATIKIL reinforcement lock is one white aluminium bolt at about £12.89, rated 3.1 from eight reviews, four of them with UK headers. Two short UK comments call it sturdy. The complaint that pulled the score down is the box: buyers read the picture as more than one lock and sent the single unit back. The listing tells you to measure the door-plate thickness first and includes four screws of 28.9 mm. The listed weight is 480 g. The 800 lb line and the claim that it prevents lock bumping are seller text, not a test cited with the listing. Unlocking is a pinch and a slide toward the hinge. Eight reviews is too small a sample to treat the stars as a fit guide.
Pros
Cons
Best for: You have measured the door-plate thickness and you only need one bolt, knowing the review sample is eight.
Less suitable: You want a multi-pack, a UK review history, or a tested force figure.
Specifications
Common questions
How many locks are in the box?
One. UK reviews say the picture looked like more than one lock, and they sent it back for that reason.
Does it fit any door?
The listing says to measure the door-plate thickness first. Unlocking is a pinch and a slide toward the hinge. No key is described.
The Koilife 301-90937 is two silver aluminium flip latches at about £7.49, with eight screws and a listed material thickness of 3.5 mm. The listing names bathroom, bedroom, barn, window, garden gate, cabinet, shed, garage and balcony doors, and describes a 90-degree corner. The pack weight is 120 g. The listing has no customer-review line and no UK review text, so there is no star rating for fit or strength. The model name says anti-theft, but the spec does not name a key or a button. You would be choosing from the picture, the screw count and the corner shape. That is too little to treat it as a tested extra lock.
Pros
Cons
Best for: You want a cheap corner latch and you can judge the fit yourself, with no reviews to read.
Less suitable: You want UK reviews, a keyed lock, or any evidence it resists a forced door.
Specifications
Common questions
What doors does the listing name?
Bathroom, bedroom, barn doors, windows, garden gates, cabinets, sheds, garages and balconies. It is a 90-degree corner latch.
Is there a UK star rating?
The listing has no customer-review line, so the rating and review count are not available.
Scores use the twelve amazon.co.uk listings on this page. There was no lab test. Stars and review counts are the UK figures on those listings. A high star line with few UK review headers is marked down. The weights below sum to 100. The highest score is the top pick. The best value is the strong score at the lowest price that still does one clear extra-lock job: the Sandiyago sash-jammer pack, with short screws and shearing spacers already deducted. A hook used to hold a gate open, and a child lever lock, are not scored as burglary resistance. None of these products is scored as BS 3621, TS 007 or a PAS 24 doorset.
UK review evidence
40%Amazon star rating, then a deduction when few UK review headers sit behind it. A 4.7 from 107 reviews with one UK header does not outrank a 4.7 from 444 reviews with 50 UK headers. No star line is scored from the listing only.
One extra-lock job
25%Whether the product does one job: sash jammer, handle clamp, portable brace, reinforcement bolt, loop latch, hook, or child lever block. A cabin hook used to hold a gate open is not scored as a night lock.
Stays set when you leave
20%Whether it can stay set when you leave. A non-locking jammer and a brace you take with you are scored for occupied use only.
Fixings and listing honesty
15%Deductions for short screws, shearing spacers, a bent frame plate, a picture that does not match the quantity, a title that contradicts the material, and seller claims (800 lb, PAS 24 on the device) that are not a UK test of your door.
Name the job, then the door, then whether the extra can stay on after you leave. A star rating does not tell you which of those you bought.
An additional door lock is a second fastening on a door you already have. It is not a euro cylinder and it is not a multipoint lock. On amazon.co.uk the same search mixes a sash jammer, a clamp for two handles, a reinforcement bolt, a portable under-door brace, a loop latch, a cabin hook and a child lever lock. Prices on these twelve listings run from about £4.99 to about £22.72. Name the job first. Extra resistance while you are in is a non-locking sash jammer or a handle clamp.
The 200 mm hook and the 75 mm pair have strong star ratings, and UK reviews mostly hold a shed, a gate or French doors open. One hook slipped. If the hook is off the eye, the door is as it was.
The locksmith guide is two sash jammers on a single door. Sandiyago reviews cite screws around 30 mm and spacers that sheared. If you cannot feel steel in the uPVC profile, stop and call a locksmith.
The 800 lb line is the seller’s text on two bolt listings. A PAS 24 line on the DoorJammer is not a PAS 24 doorset. A handle clamp on vertical levers, or a brace on an outward uPVC door, is the wrong product for that leaf.
Name the job before the brand. Extra resistance while you are in is a non-locking sash jammer or the hzuisst handle clamp. A bolt that stays slid shut is the Annakideya or the PATIKIL, and only if you can drill a solid edge. The DoorJammer is a travel brace for an inward door with at least 3 mm of gap. The Moonybaby pack blocks a lever a toddler can reach. The cabin hooks hold a gate or a shed open. Then match the door. Sash jammers in this set suit hinged uPVC, wood or composite.
On an HMO, a flat entrance or any fire route, the door must open from inside without a removable key. Park a jammer arm so it cannot drop and lock you out. Cheshire Fire and Rescue and the DASH guide both point at that keyless exit. The extra does not replace the primary lock. Timber final exits are where insurers cite BS 3621. ProtectUK points to BS 8621, a thumb-turn inside, so you are not searching for a key.
Three typical situations, each with a recommendation from this comparison.
You want a jammer on a hinged uPVC, wood or composite door while someone is in to set it. The Sandiyago four-pack is the best value at about £8.99, with 4.5 from 1,338 reviews. Screws of about 30 mm were too short for some doors, and there is no key.
You cannot drill, and the door opens inward with at least 3 mm of gap on a flat floor. The DoorJammer DJ3 is a 210 g brace at about £22.72, with 4.4 from 2,799 reviews. The maker says most uPVC doors have no suitable gap, and it does nothing after you leave.
You want to block a lever at the top of the stairs or on a bathroom, without drilling. The Moonybaby two-pack is adhesive, at about £7.99, with 4.5 from 1,250 reviews. It is ranked as a baby product. A fresh pad can be pulled off, and it is not a lock for an empty house.
The top pick is the hzuisst WH-KN6168-2. It has the highest score: 4.7 from 444 reviews, with 50 UK review headers, on white uPVC French and patio doors at about £19.99. It fits horizontal levers only, and it works only while it sits on the handles. The best value is the Sandiyago four-pack at about £8.99, 4.5 from 1,338 reviews, for a non-locking jammer on a hinged uPVC, wood or composite door. Short screws and shearing spacers are already in that score. A hook, a child lever lock or a portable brace is not treated as BS 3621, TS 007 or a PAS 24 doorset.
hzuisst French door handle lock
Highest score: 4.7 from 444 reviews and 50 UK review headers, for two horizontal levers at about £19.99. It works only while it is on the handles.
Sandiyago sash jammer, 4 pack
About £8.99 and 4.5 from 1,338 reviews for a non-locking jammer. Short screws and shearing spacers are already deducted.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources used for this page in October 2026. Prices, stars and review counts are the amazon.co.uk figures in this comparison. No lab test was run.
Expert source (DIY & tools): Charlie White (Charlie DIYte) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This page contains affiliate links to amazon.co.uk with the tag pcuk26-21. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the UK listing lines in this capture. We did not run a lab test.
