Master key installation for Knightsbridge offices, shops and mansion blocks. One key for each person, opening exactly the doors they need. Restricted keys that can’t be copied without your authorisation, and a lost key never means changing every lock in the building.
Most offices, shops and mansion blocks end up with a drawer of loose, unlabelled keys. Nobody is sure which key opens which door, or how many copies exist. A master key system replaces that drawer with a planned set of keys. Each person carries one key that opens exactly the doors they need, and nothing else. It’s the simplest way to control access across multiple doors with fewer keys.
Knightsbridge Locksmith designs, supplies and fits master key systems for businesses and buildings across Knightsbridge, Belgravia, Chelsea, Kensington and central London. We supply and fit systems from more than ten brands that can genuinely be master keyed, including EVVA, Abloy, Mul-T-Lock, Kaba, ISEO and CISA, and we can bring Banham-fitted doors into a system using compatible cylinders. Every system starts with a site survey and ends with a key register, so you always know who holds what. The survey costs £59 + VAT, and we deduct it from your order when you go ahead.
As master key locksmiths working in a single property or across a whole building, we give expert advice on the right key platform, the right access levels and the right number of keys, then handle the full master key installation.
In a master key system, every individual lock has its own individual key, often called a differ key or change key. Together, these differ keys and master keys make up a master key suite. Higher-level keys are cut to operate multiple locks as well. Who can open what is decided when the key system is designed, not by whoever ends up holding the most keys.
The grand master key sits at the top of the access hierarchy and opens all the locks in the system. Below it, each master key opens a group of doors, such as one floor or all the service rooms. Each sub master key opens a smaller group within that. At the bottom, staff members and residents carry individual keys: each person has their own individual key, which opens their own door and any shared entry points.
A single master key system has just two levels: one master key that opens several locks, each of which also has its own key. Larger, more complex systems add sub master levels, and very large estates can add a great grand master key above several grand master systems.
| Key level | Who usually holds it | What it opens |
|---|---|---|
| Grand master key | Owner, director or managing agent | All the locks in the system |
| Master key | Manager, porter or maintenance contractor | A group of doors, such as one floor, one department or all service rooms |
| Sub master key | Supervisor or team lead | A smaller group within a master |
| Individual (differ) key | Staff member or resident | Their own door, plus shared doors such as the main entrance |
A master key system is not the same as a keyed alike system. With keyed alike locks, the same key opens every lock, so anyone holding a key can open all the locks. With a master key system, different keys open different doors, specific keys are issued to specific people, and only the master keys open multiple locks. One master key replaces a whole ring of keys.
Keyed alike suits a single property with two or three doors, where everyone with a key should be able to open every door. See our same key locks service. A master key system suits commercial offices, shops and buildings where different people need different access levels.
Every building is different, but most of the master key systems we design follow one of these patterns. Each example shows who holds which key.
Commercial offices. Directors open everything, staff open the front door and their own floor, and the server room stays restricted. When someone leaves without returning a key, you replace one cylinder, not every lock.
Shops and boutiques. Managers hold the stockroom and cash office, and sales staff hold only the front door. See our commercial locksmith services for shops and offices.
Mansion blocks and managed buildings. Residents’ keys open their own flat and the communal doors. The porter’s key opens service areas but not flats, and the managing agent holds the grand master. See our service for letting agents and property managers.
Hotels, serviced apartments and clinics. Each wing, floor or department gets its own level of access, all under one system.
A master key system is the simplest form of access control. Instead of cards, codes or apps, the key system itself decides who can open which entry points. It gives convenient access to authorised people while limiting access for everyone else, and every change to access is planned, recorded and easy to audit.
As master key locksmiths, we specialise in mechanical lock systems and don’t install electronic access control such as card readers or keypads. For many offices, shops and mansion blocks, a well-designed master key system is all the access management they need.
A master key system is only as secure as its keys. A standard key can be copied in minutes at any key cutter, so a lost master key could be copied before you even notice it’s gone. That’s why we fit restricted and patented key systems.
Restricted cylinders can also be anti-snap and high-security rated. See our high-security locks.
Not every lock can be master keyed, and not all lock systems can grow into a full master key suite. Many popular home cylinders are sold keyed to differ or keyed alike only. Every brand below has a key platform that can be built into a proper master key suite, and we hold trade accounts with their suppliers. That means we recommend the right system for your building, not the one brand we happen to sell.
| Brand | Master key platforms | Best for |
|---|---|---|
| EVVA | EPS, 4KS and MCS patented systems | Offices and mansion blocks wanting long-term key control, up to very high-security suites |
| Abloy | Protec2 and Sentry disc detainer systems | High-security sites, plant rooms and outdoor doors, where pick resistance matters most |
| Mul-T-Lock | Interactive+, MT5+ and Integrator | Commercial buildings, and doors with existing Banham lock cases |
| Assa Abloy group | Master keyed cylinders across the group’s commercial ranges | Buildings already fitted with Assa Abloy hardware |
| dormakaba (Kaba) | Kaba patented master key systems | Large buildings with many key levels |
| ISEO | Patented master keyed cylinders | Offices, retail and multi-site businesses |
| CISA | Astral and other master keyed ranges | Commercial suites on a mid-range budget |
| DOM | Patented master key systems | Commercial and residential buildings |
| Avocet ABS | ABS Design master keyed cylinders | Smaller offices, shops and HMOs that want anti-snap cylinders |
| Master Key Systems (MKS) | Adapta-Prime TS007 1-star and 3-star cylinders | Cost-effective suites mixing high and standard security doors |
We design every system from scratch around your building, so it’s fully documented from day one and has room to add doors later.
This is one of the most common questions we get in Knightsbridge, because so many doors here have Banham locks. Banham’s own locks are supplied keyed to differ or keyed alike, and a Banham rim lock and mortice lock can be keyed to pass, so one key works both. That’s convenient for a single front door, but it isn’t a master key system with different access levels.
To bring Banham-fitted doors into a master key system, there are two routes:
We’ll check which route suits your doors during the survey. See also our Banham lock installation and Banham lock change services.
A master key system is built around cylinder locks, so the door cylinders and lock type on each door decide what’s possible.
| Lock type | Can it be master keyed? |
|---|---|
| Euro cylinders (most modern doors, uPVC and aluminium shopfronts) | Yes. The easiest type to master key, usually with no other changes to the door. |
| Oval cylinders | Yes, from several of the brands above. |
| Rim cylinders (night latches on period front doors) | Yes. The cylinder is swapped, and the latch usually stays. |
| Traditional lever mortice locks | Only in a very limited way. We usually replace them with a cylinder-operated mortice lock that can join the system. |
| Banham locks | Not with Banham’s own keys. Banham-compatible master keyed cylinders can be fitted (see above). |
| Padlocks, cabinet and cam locks | Often yes. Several brands make padlocks and cam locks that work on the same master key as your doors. |
Many locksmiths use “restricted” and “patented” as if they meant the same thing. They don’t, and for a master key system the difference matters.
For offices, managed buildings and any site where a lost master key would be serious, we recommend a patented system. For smaller premises where the main aim is organising access, a restricted or standard master keyed system can be enough. We’ll explain the options, and the cost difference, at the survey.
Every master key installation follows the same five steps, whether it covers one office or an entire building.
Payment is due on the day the work is completed, by card, cash, Apple Pay or Google Pay.
The cost of a master key system depends on three things: the number of doors, the brand, and the security grade of the cylinders. A small office with a handful of doors costs far less than a mansion block with dozens of flats and service rooms. Restricted, patented systems cost more than unbranded ones, because the keys are protected against copying.
The other factors are the number of keys required at each level, how complex the chosen system is, and how much spare capacity you want for future expansion. For example, a two-level single master key system for a small office costs much less than a four-level system with grand master and sub master keys.
On most doors we only change the cylinder and keep the existing lock, which keeps the cost down. After the site survey, you get a fixed, itemised quote, so you know the full price before anything is ordered. The £59 + VAT survey fee is deducted from your order if you go ahead.
Our master key locksmiths design and fit master key systems across Knightsbridge, Belgravia, Brompton, Sloane Square, Cadogan Square, Hyde Park, Chelsea, Kensington, South Kensington and Westminster, and other parts of central London. See our full service area.
It depends on the number of doors, the brand and the security grade. We give you a fixed, itemised quote after a site survey, so you know the full cost before anything is ordered. The survey costs £59 + VAT, and we deduct it from your order when you go ahead.
A grand master key sits at the top of a master key system and opens all the locks in it. Below it are master and sub master keys, which open smaller groups of doors, and individual keys, which open one door each.
No. A master key system is built on one key platform, so all the cylinders in the system must come from the same brand and range. That’s why we help you choose the right master key suite at the start, from lock systems that can grow with your building.
Yes. We design every system with spare capacity for future expansion, so new doors, floors or tenants can be added without replacing the entire system.
The site survey costs £59 + VAT. If you go ahead with the master key system, we deduct the full survey fee from your order, so it costs you nothing extra.
Usually, yes. If your locks use euro, oval or rim cylinders, we normally replace only the cylinders and keep the locks.
Not with Banham’s own keys. Banham locks are supplied keyed to differ or keyed alike. To include Banham-fitted doors in a master key system, we can fit Banham-compatible master keyed cylinders into the existing lock cases, or fit new master keyed locks.
We supply and fit master key systems from EVVA, Abloy, Mul-T-Lock, the Assa Abloy group, dormakaba (Kaba), ISEO, CISA, DOM, Avocet ABS and MKS. Many popular home cylinders can only be keyed alike, so we’ll always check that the brand you choose supports the system you need.
Restricted keys are only supplied to selected dealers, which limits copying but doesn’t legally prevent it. Patented keys are protected by a patent, so copies can only be made against the key card or registration. For most commercial master key systems we recommend a patented system.
With keyed alike locks, one key opens every lock. With a master key system, each lock has its own key, and higher-level keys open groups of locks. Keyed alike suits a small home, while a master key system suits buildings where different people need different access.
With a lower-level key, only the cylinders that key opens need changing. A lost grand master key is the most sensitive, so we recommend recoding or replacing the cylinders it affects. Restricted keys can’t be copied at a key cutter, which buys you time.
No, as long as it uses restricted keys and a proper key register. Most key-related security problems come from uncontrolled copies, and a restricted system is designed to prevent them.
Restricted keys can only be supplied through us or the manufacturer, and only when an authorised person at your business requests them. That’s what stops anyone copying a key without your knowledge.
A small office or shop can usually be fitted in one visit, and larger buildings floor by floor. The main wait is the manufacturer making your restricted keys. We give you the lead time with your quote.
Yes. We fit master key systems early in the morning, in the evening or at weekends, so your business or building keeps running.
Book a site survey. We’ll map your doors, design your key plan and give you a fixed quote. The £59 + VAT survey fee is deducted from your order when you go ahead.
Knightsbridge Locksmith, a mobile locksmith service: we come to you anywhere in Knightsbridge and central London. Open 24 hours, 7 days a week.