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Crenshaw Lock

Master Key System in Monrovia · 24/7 mobile

Master Key System in Monrovia, California

Crenshaw Lock Company designs and installs master key and restricted key systems with real key control for Monrovia, California businesses and properties. We are fully mobile and available 24/7, so we come to you. Call (323) 997-8867 to talk through your doors and who needs access to them.

  • Mobile to your Monrovia location
  • Available 24/7
  • Price quoted before we start
Call (323) 997-8867or tap to call — we answer 24/7
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A master key system sounds simple: one key opens many doors, while other keys open only some. In practice, a good system is a plan about people. Who needs access to what, who should never have it, and what happens when a key goes missing or an employee leaves. We build that plan around your actual building, then pin the hardware to match.

Monrovia has an unusual mix of properties for this work. Along Myrtle Avenue in Old Town, small shops and restaurants often have locks of different ages, installed by different owners over the years, so nobody is sure how many keys are out there. Multi-tenant buildings, offices, churches, and rental properties around Mayflower Village and near the Metro A Line station have their own needs, such as a landlord key that reaches common areas but not private units.

Crenshaw Lock has served Greater Los Angeles and Ventura County since 1987, and owner David Shar has seen how systems succeed and how they fail. The failures are usually poor record keeping or a system that was never allowed to grow. We design for both, and we are mobile only, so there is no storefront to visit. We work on site, at your door, at a time that suits your operation.

How it works in Monrovia

  1. 1

    Walk the property and map every door

    We start on site, whether that is a Myrtle Avenue storefront, an office suite, or a larger property in North Monrovia. We list every lock, note its brand and condition, and identify which ones can be keyed into a system and which should be replaced.

  2. 2

    Define the access hierarchy

    Together we decide who needs what: a grand master for ownership, masters for managers or departments, and change keys for individual doors or tenants. We also plan for growth so adding a door or a tenant later does not force a redesign.

  3. 3

    Choose the level of key control

    A standard system uses keys that can be copied at many places. A restricted keyway adds protection, because duplication requires authorization. We explain the tradeoffs honestly so you can match security to your actual risk and budget.

  4. 4

    Pin, install, and test the hardware

    We rekey or replace cylinders and pin them to the agreed hierarchy, then test every key on every door. Each key should open exactly what it is supposed to open and nothing else.

  5. 5

    Document and hand over the system

    You receive a clear key schedule showing which keys fit which doors, and we talk through how to issue, track, and recover keys. Good records are what keep a system working years later.

  6. 6

    Support changes over time

    When a manager leaves, a tenant moves out, or a key goes missing, we can rekey the affected cylinders without redoing the whole building. Call (323) 997-8867 any time, day or night.

Need master key system in Monrovia?

24/7 Mobile Locksmith across Greater Los Angeles & Ventura County. We answer 24/7.

Call (323) 997-8867

What affects the price

  • The number of doors and cylinders that must be keyed into the system.
  • How many levels the hierarchy has, such as grand master, master, and change keys.
  • Whether you choose standard keyways or a restricted keyway with patent-protected key control.
  • The condition and age of existing hardware, since worn or mismatched locks may need replacing rather than rekeying.
  • The number of keys needed per person or department, and whether keys must be cut up front.
  • Scheduling needs, such as working after hours around a restaurant or shop's open hours.

Why Monrovia chooses us

  • Fully mobile service. We do the work at your property, with no shop visit needed.
  • Available 24/7, which matters for businesses that cannot disrupt daytime operations.
  • In business since 1987, with the experience to design a system that holds up as staff and tenants change.
  • Honest guidance on when a restricted keyway is worth it and when a standard system is enough.
  • Clear documentation of your key schedule so you are not dependent on memory.
  • Comfortable with mixed-age hardware, from older storefront locks to modern commercial cylinders.

Master Key System across Monrovia

Monrovia's commercial heart is Old Town, where Myrtle Avenue storefronts, restaurants, and shops sit near Library Park and the historic Aztec Hotel, a Route 66 landmark. Many of these buildings have accumulated locks over decades, which makes a master key project especially useful. Properties in the 91016 ZIP code often benefit from a clean-slate system and a single record of who holds keys.

Further out, Mayflower Village has its own mix of small businesses and multi-unit properties, while the commuter traffic along I-210, Huntington Drive, and Foothill Boulevard keeps offices and service businesses busy. Landlords near the Metro A Line station often need a system where common areas open with one key and individual units stay private.

North Monrovia in the foothills, including addresses in 91017 toward Monrovia Canyon Park along Mountain Avenue, has larger lots with side-yard gates and long driveways. A restricted system can bring house, gate, and outbuilding locks under one organized scheme for estates, rentals, and properties with several users.

Locked out or need a locksmith now?

24/7 Mobile Locksmith across Greater Los Angeles & Ventura County. We answer 24/7.

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Other Monrovia locksmith services

See all of our Monrovia services, or our citywide master key system page.

Master Key System in Monrovia — FAQs

What is a master key system?
It is a set of locks and keys arranged in a hierarchy. Each door has its own key, while higher-level keys open multiple doors. A grand master can open everything, and a change key opens only one. Call (323) 997-8867 to discuss a design.
Can you work with the older locks in my Old Town Monrovia building?
Often yes. We inspect the existing hardware and rekey locks that can be included. Locks that are worn or incompatible may be better replaced, and we will tell you which is which.
What is a restricted key system?
A restricted keyway uses key blanks that are not freely sold, so copies require authorization. It adds control over who can duplicate keys. It is a good fit when you want tighter accountability.
Do I need a master key system for a small shop?
Not always. If you have only a few doors and few key holders, simple rekeying may be enough. A system makes more sense when several people need different levels of access.
Can I add doors or tenants to the system later?
Yes, if the system is designed with growth in mind. We plan the hierarchy so new doors or tenants can be added without rekeying everything. Call (323) 997-8867 when you need changes.
What happens when an employee leaves with a key?
We can rekey the affected cylinders so the missing key no longer works. A well-documented system makes it clear which doors are affected, so the fix is targeted.
Do you have a shop in Monrovia I can visit?
No. Crenshaw Lock Company is fully mobile. We come to your property, which means we can assess your actual doors and install the system on site.
Can you work outside business hours?
Yes. We are available 24/7, so we can schedule work around restaurant service or shop hours. Call (323) 997-8867 to arrange a time.
DS

Reviewed by David Shar — Owner & Lead Technician

Crenshaw Lock Company has served Greater Los Angeles & Ventura County since 1987.

Last updated 2026-10-12.

Call (323) 997-8867 · Open 24/7