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What is Sherlock?

Sherlock is a clever combination of hardware and software which lets you and those you trust enter your home without using keys, even when you are not at home. Better still, it can unlock both your building door and your apartment door, which means it works in all types of buildings and does not require you to change your locks.

Why did onefinestay create and develop Sherlock?

With thousands of homes in Europe and North America, onefinestay manages a lot of keys - we have even developed a secure chain-of-custody systems to manage them all. Naturally we began thinking about how to reduce that complexity, while also increasing our members’ security and making life easier for guests.

Haven’t I read about other systems like this?

There are several other solutions to replace keys with a smartphone app, but none can claim to do what Sherlock can. Most are geared towards the North American market and require you to change all your locks—if you live in a walk up, both the one on your apartment door as well as your building door—which makes them far too expensive and difficult in most cases. Additionally, some other systems rely on batteries to power the device, so if they run out of power (which they often do) you are locked out. Sherlock is the only product able to unlock both the communal door and the apartment door with the same device.

So how does Sherlock work?

A box around the size of a deck of cards, is installed inside your home, near your entry phone. And because it integrates into the existing entry phone system, Sherlock doesn’t require you to change the locks on your building door, nor make any changes in common areas of your apartment building or walk-up.

If you don’t have an entry phone, or it isn’t already wired to the front door of your apartment or house, Sherlock comes with an electric strike, which allows you to open your existing lock without the need for a key. This is then connected to the device via a discreet, thin white cable.

What is an ‘electric strike’?

An electric strike is the part of the lock that sits on the doorframe and releases the bolt when you press the buzzer on your entry phone. Electric strikes are a standard component sold and installed by locksmiths the world over. If you already have one on your door, Sherlock connects into it directly or via your entry phone system. If you don’t have an electric strike on your door, they are simple for any locksmith or Sherlock technician to install.

Just how secure are these electric strikes?

Sherlock is controlled using our mobile application available for Android and iOS. When you want to unlock your door using Sherlock; you open the app and enter in your PIN, our servers then process your request, confirm your authorisation status, and then relay the request in an encrypted form to the wireless receiver inside Sherlock. The box then tells the electric strike to release for a few seconds before securing again.

How do I associate my mobile devices to use my Sherlock?

During the installation process we’ll ensure your device, your email address, the electric strike and our servers are all connected. And after you login to the app and register your device to be able to issue commands to your Sherlock system, you can use Sherlock to unlock your door.

Can Sherlock open more than one door?

We have specifically designed Sherlock to work in homes with one door as well as homes which have a communal entry point and then another, private door, such as walk-ups or apartment buildings. In this respect Sherlock is the only keyless entry system that offers this functionality.

How does Sherlock know to open both my communal and apartment door?

When we install Sherlock, we make sure the device is correctly configured to open the correct number of doors in your property. You are also able to set the optimum amount of time for your first and second doors to remain unlocked (typically 10-30 seconds depending on long it takes to walk from your building door to your apartment door).

How exactly does Sherlock unlock my apartment door?

When you ask Sherlock to unlock the door using the app, the Sherlock device communicates to our servers, checks that everything is in order and then instructs the electric strike to unlock. After a set period of time (typically 5 seconds) the electric strike then secures itself, regardless of whether the door has been open or not.

And does Sherlock do the same to open my building’s communal door?

In the case of your building’s communal door (if you have one), Sherlock works via your existing entry phone system. That means no changes are made to any of the communal areas and you can remotely control your communal door without affecting anyone else’s entry phone. All without anyone having to change their locks or issue new keys.

How long do my doors stay unlocked once I have opened them with Sherlock?

Depending on the type of lock you have, Sherlock defaults to keeping your building door unlocked for about five seconds. The lock in your apartment door will be held open for a specific time, adjusted individually for the time it takes for you to travel from the first door to the second.

Can I use Sherlock when I’m not at home?

Absolutely, this is main reason Sherlock was designed. As long as you have the app with connection to mobile data or a WiFi connection you can use Sherlock from anywhere in the world.

What will Sherlock allow me to do that I can’t currently do with my traditional keys?

With Sherlock you no longer have to wait at home for the delivery man or contractor to arrive and it means no more frantic dashes home to let in friends and loved ones. No more cutting of keys for your house guests/ cleaner. No more replacing lost keys.

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Sherlock is compatible with a variety of homes and doors

What types of homes does Sherlock work with?

Through running our Beta Test in London, we have found that Sherlock works with the majority of home entry systems. Sherlock is also compatible with most types of doors.

Do I need new locks if I want to use Sherlock?

You most probably do not. The most common way Sherlock integrates with a door is via a latch style lock. These are locks that secure your door without the need for a key, i.e. when you pull to door shut behind you it automatically secures and you can not get back in. Normally these locks are installed with a solid metal keep or strike (the part that is on the door frame which the bolt interacts with). We replace this part with and electric strike when we install Sherlock. Nothing else needs to change, and your keys stay the same.

What type of phones does Sherlock work with?

The Sherlock mobile app is available on both iOS and Android which means that Sherlock is compatible with around 82% of smart mobile phones worldwide. And 92% of all smartphones purchased in the UK last year.

Can anyone else use Sherlock?

Part of what makes Sherlock so handy is that you can share access with people you trust. There is no limit on the number of different guests and administrators that you can register to use your device, so you can give access to your friends, family, cleaner – or anyone else you would trust with keys to your home. Of course, you can track who has access and immediately revoke your virtual keys at any time.

Will Sherlock affect my neighbour’s entry phone?

Not at all. Sherlock was designed to prevent this and installing Sherlock has no effect on anyone else’s entry phone to date.

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To know is to be secure

How is having a box more secure than using my keys?

Keys have a lot of limitations. Lose one and you may have to change your locks. Similarly if you give someone a key, they are able to make copies without your permission or knowledge.

Sherlock helps to reduce this risk by using virtual keys. If you decide that someone should no longer be allowed access to your home, you can revoke their virtual key at any time - and there is no danger of them making unauthorised copies.

Could having Sherlock installed affect my home, and contents, insurance?

onefinestay members who install Sherlock will continue to be covered by our existing insurance while we’re in charge of your home. For those times when we’re not in charge of it, or for those Sherlock users outside of onefinestay, we suggest that you check with your home insurance provider for a definitive answer.

Does Sherlock work if I have multiple locks on my door?

Sherlock controls one lock per door. If your apartment door has more than one lock, we recommend upgrading your primary lock to a high security unit, so that you don’t need to use a separate deadbolt. These more secure units feature an auto-deadlocking which means that urchins would not be able to slide in a credit card. We also recommend that you chose a lock with a secure cylinder, such as the Yale X5, which is designed to be bump resistant. Even if you do install additional locks, it is usually possible to keep your current keys by transferring the barrel.

What if Sherlock doesn’t work?

In the unlikely event that Sherlock is unresponsive, your doors will remain secure and your traditional keys will always work.

What if I lose my phone?

Before opening any doors, the app will always require you to verify the opening command by either entering a PIN or TouchID. In addition, changing the password for your sherlock account on our website from any other computer or smartphone will render any previous app sessions void effectively logging you out of all previously used devices to guarantee that nobody can use your Sherlock. In the meantime, if you want to get into your home your traditional keys will still work.

What if there is an issue with the power/ my phone malfunctions?

The Sherlock system is configured to always fail secure. This means that if the device finds itself offline for any reason, your doors remain closed and secure whilst you can rely on a spare set of keys to gain access again.

Do you keep a track of who comes into my home?

Logs of which users opened which doors and when are kept for your peace of mind for 30 days in our secure systems. These logs are deleted after 30 days and can be reviewed by the device owner upon request.

How secure is the communication between the device and your servers?

All Sherlock traffic to our servers uses the HTTPS protocol (where the ‘S’ stands for secure) in the same way as online banking, guaranteeing that messages are encrypted using the latest SSL/TLS standards. All communication goes through the same security measures that we apply to take multi thousand pound bookings.

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I want my very own Sherlock. Can I have one? Please?

If you would like to make a purchase and arrange an installation please get in touch at

Why is this service called Sherlock?

As any reader of Arthur Conan Doyle will tell you, there is simply no one better than the brilliant detective at explaining the mystery of how one can get into – and out of – a locked room, when there are no keys in sight.