Nuki Smart Lock Ultra review
By Tom Calder
Key specs
The maker's figures.
- Type
- Replaces existing cylinder with Nuki's Universal Cylinder
- Access methods
- App (BT/WiFi/Matter), auto-unlock, optional keypad
- Battery life
- Rechargeable, ~2hr recharge, months per charge
- Insurance
- Replaces cylinder — no BS3621/Sold Secure claim of its own
Technically the most capable Nuki we compare, with integrated WiFi, Matter support and a genuinely fast two-hour recharge — but installing it means physically swapping your existing door cylinder for Nuki's own Universal Cylinder, which carries no BS3621 or Sold Secure rating of its own, so it needs a clear-eyed insurance check that the clamp-on Nuki Smart Lock Go doesn't.
- Best for
- Buyers wanting the most integrated Nuki experience (built-in WiFi and Matter) who are happy to replace their cylinder entirely and check BS3621 compliance separately.
- Skip it if
- You need to keep a BS3621-rated cylinder in place for your insurance
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Built-in WiFi and Matter support without needing a separate bridge
- Recharges fully in around two hours via the included magnetic cable
- Works with the optional Keypad 2.0 for fingerprint or PIN entry
Worth knowing
- Replaces your existing door cylinder rather than clamping onto it, so any BS3621-rated lock you currently have is removed, not left in place
- Nuki makes no BS3621 or Sold Secure claim for the Universal Cylinder that comes with it
- The most expensive lock in this comparison
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Our review
Nuki's smallest and quickest lock: a 57mm stainless steel knob with a brushless motor, Wi-Fi and Matter over Thread inside, and a battery that refills in two hours. The fact that decides it is the cylinder change: Nuki's own cylinder comes in the box and replaces the one in your door. It suits an owner-occupier with a euro-profile door who wants everything in one unit and will change the cylinder to get it.
What it is
Nuki says the Ultra is its first smart lock with a brushless motor. Nuki gives it as ⌀57 x 58mm and 250g in stainless steel, rated for 10 to 40°C, and quotes under 1.5 seconds to lock or unlock a double-turn lock in its fastest mode. Nuki lists a cylinder change as required: the Universal Cylinder in the box replaces the one in your door, so your current cylinder comes out. Nuki rates that cylinder SKG three-star, with EN 1303 and DIN 18252 certification and a drill-resistant body; three keys are in the box.
Will it fit your door
Nuki's compatibility guide covers euro-profile and Swiss round cylinders only, and its limits are about the door: measured from the retaining screw, the inside must be no more than 68mm to the inner door plate and the outside no more than 55mm to the outer plate, with extensions sold for longer outsides. Nuki also asks for more than 30mm from the keyhole centre to the frame and handle on an inward-opening door, and more than 40mm to the frame and 30mm to the handle on an outward-opening one. Nuki says the motor can drive multipoint locks, but on a lift-to-lock uPVC or composite door the handle must still be lifted by hand: the motor only turns the cylinder. Nuki says fitting takes about 15 minutes with no drilling.
In a UK power cut
The lock runs on its own battery, so a power cut does not stop it working at the door over Bluetooth, and Nuki's emergency function lets the supplied keys open the door with the lock still fitted, so a flat battery does not shut you out. Remote access does stop: the built-in Wi-Fi needs your router, and Matter over Thread needs a powered hub that is also a Thread border router. The cable is USB-C, so a charged power bank can top it up during a long cut. See power cut preparation.
How it compares
Nuki's clamp-on choice on our pages is the Smart Lock Go (2025) with Keypad: it fits over your cylinder so your key keeps working, runs on four AA cells and includes a 200-code keypad, but it has a larger 110 x 60 x 60mm body and Nuki sells remote access for it as an extra. The SwitchBot Lock Pro also keeps your cylinder, adds British oval and Swiss round fits, runs six to nine months on four AA cells by SwitchBot's figure, and needs a SwitchBot hub for remote control. More in the SwitchBot vs Nuki guide and our smart locks comparison.
Insurance and what Nuki does not claim
Nuki's certifications are continental: SKG is the Dutch mark, EN 1303 the European cylinder standard and DIN 18252 the German one. No Nuki UK page we read names BS 3621, TS 007 or Sold Secure, the standards British policy wording tends to use. Nuki says the Ultra preserves or enhances a door's security class and needs no insurer notification; treat that as the maker's view. If the cylinder you remove carries TS 007 stars or a Sold Secure mark, that rating leaves with it: ask your insurer in writing and keep the old cylinder. Our anti-snap cylinders page explains the stars.
Living with it
Nuki publishes no runtime beyond months per charge, so watch the app for the first weeks. The box holds a 2m USB-C cable, and the app manages up to 200 access permissions. Fingerprint or code entry needs the separate Keypad 2, rated for 20 fingerprints, 200 codes and IP54. Nuki's UK shop gives 30 days to return under Austrian-law terms and cites the two-year statutory warranty; Guarantee Plus, bought within 30 days of activation, extends cover to three years.
Our verdict
Buy the Ultra if you own the house, have a euro-profile door inside Nuki's 68mm and 55mm limits, and want the smallest unit with Wi-Fi, Thread and a fast recharge in one piece. Skip it if you rent, if your insurer named a cylinder standard, or if you like your current key: a clamp-on lock such as the Nuki Go (2025) or the SwitchBot Lock Pro leaves the cylinder alone, though neither has Wi-Fi built in.
A researched review, built from the maker's specs, manual and UK listings; facts checked 21 Oct 2026. Sources: Nuki UK — Smart Lock Ultra product page (⌀57 x 58mm, stainless steel body, brushless motor, speed modes, two-hour recharge, months per charge, 20% warning, Universal Cylinder replaces the current cylinder, built-in Wi-Fi, Matter over Thread, not compatible with the Nuki Bridge, Universal Cylinder SKG***, EN 1303, DIN 18252, emergency function, 15-minute fit, security-class statement); Nuki — Smart Lock Ultra datasheet, October 2024 (250g, 10–40°C, lithium-polymer battery, Bluetooth/Thread/Wi-Fi 2.4GHz, speed-mode timings, up to 200 access permissions, box contents, three keys, modular extensions); Nuki UK — Smart Lock Ultra compatibility guide (euro-profile and Swiss round; 68mm inside and 55mm outside limits; keyhole clearances; multipoint note; indoor side only); Nuki UK — Keypad 2 (fingerprint or code; 20 fingerprints and 200 codes; IP54; Bluetooth to the lock); Nuki UK — Guarantee Plus (two-year statutory warranty; extension to three years; buy within 30 days of activation); Nuki — general terms and conditions (30-day return period, free return, Austrian law).
Who shouldn't buy this
Skip this if you need to keep a BS3621-rated cylinder in place for your insurance; look at the Nuki Smart Lock Go instead, which clamps onto your existing cylinder without replacing it, or Nuki's separate Ultion-cylinder bundle if you want BS3621 compliance built in.
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for Homeowners who want to add app and PIN access to an existing UK cylinder lock without swapping out their current deadlock.
Best for Households wanting to replace their entire door handle with a keyless smart handle rather than just adding an actuator.
as of 4 Nov 2026, 19:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for Adding app and keypad entry to an existing door lock without changing the cylinder, at Nuki's lowest price.
as of 4 Nov 2026, 19:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Questions
Does the Nuki Smart Lock Ultra replace my door cylinder?
Yes. Nuki lists a cylinder change as required: the Universal Cylinder supplied with the Ultra replaces the one in your door, so the old cylinder comes out and three new keys come in.
How long does the Nuki Ultra take to charge, and how long does it last?
Nuki quotes two hours for a full charge, on or off the door, through a magnetic USB-C cable. On runtime Nuki says only months per charge, varying with use, door and speed mode, with a warning at 20%.
Does the Nuki Ultra need a bridge for remote access?
No. Wi-Fi is built in, and Nuki says the Ultra is not compatible with the Nuki Bridge. Matter over Thread is optional and needs a Thread border router.
Can I still use a key with the Nuki Ultra?
Yes: the three keys supplied with the Universal Cylinder open the door through Nuki's emergency function with the lock still fitted, so a flat battery does not shut you out. Your old keys will not, because that cylinder is gone.
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