Smart locks: the honest guide from a locksmith

Most locksmiths who write about smart locks are also trying to sell you one. We aren’t, so this guide can be blunt about what they do well, where they fall down, and the single thing that matters more than any feature on the box.

Why won’t you fit smart locks?

Fitting them well is a specialism we choose not to claim, and half-fitting one is worse than none. A smart lock lives or dies on the lock underneath and on matching the right retrofit to your door — get either wrong and you have spent good money making the door no safer. We point you at the part that protects you.

That honesty cuts the other way too: if a smart lock genuinely suits your life, get one — from a trade that fits them properly. Our job here is to make sure you buy it for the right reasons, with the right lock doing the real work beneath it.

Why won’t the lock from the advert fit my door?

Because most smart locks are designed around a single American deadbolt, and your door almost certainly isn’t. British front doors are usually uPVC or composite with a multipoint lock: you lift the handle and a row of hooks engages along the whole edge. A deadbolt motor has nothing to drive.

So on a British door a smart lock is really one of three retrofits, and which one fits depends on the gearbox already behind your handle:

1. A motorised euro cylinder. It turns the key for you. Your handles and door stay as they are — but if your door needs the handle lifted to throw the hooks, a cylinder alone can’t do that lifting.
2. A smart handle or escutcheon. This drives the multipoint gearbox itself, so it can lift and lock. It is the only route that genuinely automates a lift-to-lock door, and the most involved to fit.
3. A keypad or fob unit paired with conventional hardware. No app required to open the door — codes and fobs do the work, with the mechanical lock unchanged underneath.

Are smart locks actually less secure?

Not inherently — but they add new ways to fail without removing the old one. A traditional lock has one attack surface: the mechanism. A smart lock keeps it and adds Bluetooth, Wi-Fi, a cloud account, an app, and your password habits. The mechanical attack is still the one burglars use, so the cylinder matters most.

The hidden weakness is where the budget went. Many smart locks pour their engineering into electronics and the app while bolting it to a basic mechanical core — so the lock survives a hacking attempt it was never going to face and fails to a screwdriver in seconds.

What should you check before buying any smart lock?

Check the boring mechanical things first, because they are what protect you. Below is the short list we’d run through with a friend — physical strength, a guaranteed way in when the electronics fail, and insurance wording — before a single app feature gets a look in. If a lock can’t clear these, no amount of remote unlocking redeems it.

• A physical key backup, always. Never fit a lock with no mechanical override. When the electronics fail — and one day they will — you need a way in that doesn’t need a charge.
• A kitemarked cylinder underneath. Snap-resistant, to TS 007 or Sold Secure, doing the real work. This is the part an insurer cares about and a burglar tests.
• Local operation, not cloud-only. Codes, fobs, and the key should work with the internet down. A lock that needs the cloud just to open is a single point of failure on your own front door.
• Your insurer’s lock wording, read first. Policies name standards, not brands. Confirm the door still meets yours with the smart hardware fitted.

When is the honest answer just a better lock?

Whenever the mechanical base wouldn’t survive an attack, which is more often than people expect. If your cylinder isn’t snap-resistant, or the gearbox is tired, that is the real vulnerability — and putting a smart handle on a weak door is decoration, not security. The fix that genuinely changes your odds is replacing the lock underneath with a kitemarked, snap-resistant one.

That is the part we do offer, plainly and without an app: a straight lock replacement with the cylinder and gearbox that should have been there in the first place. Sort that, and a smart lock on top — if you still want one — is finally protecting something worth protecting.

The short version, if you skipped to the bottom

We don’t fit smart locks because fitting them well is a specialism, and a half-fitted one is a liability. If you want one, buy it on the strength of the cylinder and gearbox underneath, demand a physical key backup, and read your insurance wording. And if the lock under the electronics is the weak point — which it usually is — the upgrade that actually matters is a snap-resistant lock, no app required.