Key Lock Box Review — Master Lock 5400EC Portable Key Safe

Master Lock 5400EC Review (2026) — Is a Key Lock Box Safer Than a Key Under the Mat?

Every household eventually needs somebody else to get in: a cleaner, a dog walker, a builder, a carer, a teenager who has lost a key again, or a guest arriving four hours before you do. The traditional answers are all bad. A key under a plant pot is the first place anybody looks, and cutting extra keys means handing out copies you cannot take back.

A key lock box is the compromise everyone eventually reaches. This is the Master Lock 5400EC: a metal shackle box holding up to five standard keys, opened with a four-digit code you set and can change. The strength is controlled, revocable access with no copied keys. The compromise is that it is a deterrent, not a safe, and where you hang it matters more than what it is made of.

In short: the key lock box earns 8.8/10 from the Blue Rays Technologies team. The rest of this key lock box review sets out exactly how that score was reached.

Key Specifications

Published specifications for the key lock box, taken from the manufacturer listing.

Everything that follows is based on those published figures for the key lock box, together with aggregated owner feedback from verified buyers.

Portable Versus Wall-Mounted, and Which You Need

This is the shackle version, which hangs on a door handle, a gate, a railing or a fence rather than bolting to a wall. That makes it the right choice for a rented home, a holiday let you do not own, or anybody who needs it in a different place next month.

The vinyl coating on the shackle exists so it does not scratch a painted door or a powder-coated handle, which sounds trivial until you are the tenant explaining the marks. Installation takes about five seconds and leaves nothing behind.

The trade is security. A wall-mounted box has to be attacked in place; a portable one can be removed and worked on somewhere quiet. If the box will live permanently at one address and the wall allows it, the bolt-through version of the same product is the stronger choice.

What a Key Lock Box Actually Protects Against

It protects against the realistic threat, which is somebody trying the obvious hiding places. A key under a mat, on a ledge above the door or inside a fake stone takes seconds to find, and that is how most opportunistic entries of this kind happen.

It does not protect against a determined attack with tools and time. No portable combination box does, and anyone selling one as burglar-proof is overselling it. What it buys is time, visibility and the fact that an intruder standing at your front door working on a metal box looks exactly like an intruder.

The revocability is the underrated part. A cleaner who no longer works for you keeps any key you cut them until they choose to return it. A four-digit code you change in ten seconds removes their access completely, and that is a genuinely different security model.

Where to Hang It, and the Mistake Almost Everyone Makes

Do not hang it on the door it opens. A box on the front door handle tells anyone passing that the key to that door is inside it, and puts the attacker in the one position where working on it looks legitimate.

Better positions are around a side gate, on a railing at the back, on a downpipe bracket out of sight of the street, or on a garage door handle. Anywhere that requires somebody to already be on your property, and where they can be seen while they work.

Set a code that is not a house number, a birth year or four repeated digits, and change it whenever somebody stops needing access. The dials are covered by a shutter, which keeps rain and grit out and also means the code is not on display between uses.

Limitations and Compromises

No product is without compromise, and the key lock box has a clear set of them.

It is a deterrent rather than a safe. A portable shackle box can be removed and attacked elsewhere, and no product of this type resists sustained effort with the right tools. Treat it as a way to avoid hiding a key badly, not as a strongroom.

Five standard keys is a real limit. Modern security keys, car fobs and anything with a plastic head take considerably more room than the figure suggests, and two or three is a more honest capacity for a household with a fob on the ring.

Some home insurance policies take a dim view of keys stored outside the property, particularly where a claim involves no sign of forced entry. It is worth reading the policy wording before relying on one, on either side of the Atlantic.

Setting the Code, Weather and Long-Term Use

Set your own combination before it goes outside, and write it somewhere that is not a note in your phone called Front Door. The reset procedure is mechanical and takes under a minute with the box open.

Spin the dials away from the code after every use. Leaving them on the last-used number is the equivalent of leaving a safe ajar, and it is the single most common way these are defeated.

Once a year, open it and check the keys have not corroded together. The shutter keeps rain off the dials, but a box on a north-facing wall in a wet winter gets damp inside, and a light spray of a dry lubricant on the mechanism keeps the dials turning cleanly.

Who Should Buy It?

The key lock box suits some households far better than others.

• You need to give a cleaner, carer, dog walker or builder controlled access
• You rent and cannot drill a box into the wall
• You run a holiday let or a rental that changes guests
• You want access you can revoke without collecting a key back
• You currently hide a key somewhere and know it is a bad idea
• You want something you can move to a different door or gate later

Look elsewhere if any of the following describes you.

• You want a genuinely attack-resistant safe rather than a deterrent
• You can bolt a wall-mounted box on permanently, in which case buy that
• You need to store more than about three modern keys with plastic heads
• Your insurance policy explicitly excludes keys held outside the property
• You are willing to fit a smart lock and skip physical keys altogether

The Verdict

Within the category this is the reference product, and the numbers show it: 4.7 from more than twenty-five thousand ratings is an unusually strong record for any piece of domestic security hardware. The shutter over the dials, the vinyl-coated shackle, the resettable code and the fit on ordinary door knobs are all small decisions that make it get used rather than abandoned.

It scores 8.8 because it does its actual job — replacing a badly hidden key with controlled, revocable access — almost perfectly, and because the things it cannot do are inherent to portable boxes rather than faults in this one. Hang it away from the door it opens, change the code when people change, and it is hard to beat.

Review score for the key lock box: 8.8/10. Strong on brand record, weather protection, code revocability, fitting and evidence base; the compromises are that a portable box can be removed, five keys is optimistic for modern fobs and some insurers dislike external key storage. Blue Rays Technologies researches independently and earns a commission from qualifying purchases, which never affects the score.

If you want to see the current price, the full options and the latest buyer feedback, it is listed as the Master Lock 5400EC Portable Key Lock Box on Amazon. Deciding what genuinely needs securing is the first step, and the Ready.gov guidance on safeguarding critical documents and valuables is a sensible checklist to work through.

Frequently Asked Questions

The questions buyers ask most often about the key lock box, answered plainly.

Is a key lock box actually secure?
It is a strong deterrent rather than a safe. It defeats anyone searching the obvious hiding places, and it does not resist a determined attack with tools. Hang it out of sight of the street and away from the door it opens.

How many keys does it hold?
Master Lock rates it at five standard house keys. Modern security keys and anything with a plastic head or a fob take far more room, so two or three is realistic for most households.

Can you change the combination?
Yes, at any time, using a mechanical reset with the box open. That revocability is the main advantage over cutting spare keys you can never get back.

Will it survive being outside all year?
The metal body is weather resistant and a shutter door covers the dials against rain and grit. Check it once a year and keep the mechanism lightly lubricated.

Related Reviews

If the key lock box is not quite the right fit, these Blue Rays Technologies reviews cover the nearest alternatives.

• DEEIRAO keyhole light review — for finding the lock once you have the key
• DocSafe fireproof document box review — securing what is inside instead
• JIKIOU manual paper shredder review — from today’s batch

Last updated: 6 September 2026. Pricing and availability for the key lock box change frequently; check the retailer listing for the current figure.