Neglected key records and unaccounted-for duplicate keys lead to Master Key System failures. The longevity of a system depends on how carefully it was planned, as well as how rigorously it is maintained. Failure to follow proper key management policies leads to compromised security.

Keys attached to numbered tags, which will be hung in a key cabinet and tracked with a spreadsheet or key tracking software

Anderson Lock creates, installs and maintains Master Key Systems. New systems represent a significant investment which provide not only convenience, but many years of reliable building security when strict key policies are established and followed.

Keys get lost. People retire… and get fired. To assure that a new key can be created within a Master Key System, we design “expansion” into each level. Because of mathematical limitations, expansion must be planned in advance. Then, when a customer calls, asking for a replacement key (and re-pinned cylinder), we reference their system’s key codes which are stored in our secure key code room. [A key code is a series of numbers used by locksmiths to create a key.] The next available code will give access to the lock, and also assure that it can still be operated by keys on every “level” above it.

In large systems more than one keyway will be used to increase security and allow for more future expansion. A keyway is a unique shape or configuration applied lengthwise (as opposed to the cuts applied to one edge of a key); this shape, or “section”, restricts other keyway shapes from being inserted into a cylinder. A Great Grand Master Key can be an all-section key. Grand Master and Sub Master Keys can be multi-section keys, that is, all A keys could be one keyway, and all B keys could be a different keyway. Like all expansions within key systems, there are a limited number of keyways. (See the ALLEGION chart below.)

The key “levels” are defined as follows:

  1. GGM – Great Grand Master Key– This key will open all subsequent key systems under it, including Grand Master, Sub Master, and Change Keys.
    1. In large MK systems, the GGM may be an all section key
    2. Key symbol GGM or GGMK
  2. GM – Grand Master Key– This key gives access to the multiple master keys and the subsequent change keys under those.
    1. Named alphabetically, A, B, C…and so on
    2. Every key symbol under the A Grand Master will begin with A, as in AA, AB, AC…and so on
    3. Every key symbol under the B Grand Master will begin with B, as in BA, BB, BC…and so on
  3. Sub Master Key– The Sub Master key is able to lock and unlock all of the change key locks prioritized below it within a given system.
    1. Also named alphabetically, AA1, AA2, AA3…and so on
    2. Key symbols under the B Sub Master will all begin with B, as in  BA1, BA2, BA3…and so on
  4. Change Key– This key will open only one lock. The change key’s corresponding lock can also be opened by all Master Keys above it within the hierarchy.
    1. Key symbols indicate where in the hierarchy the key is assigned
    2. Change Key symbols under an A Master and AA Sub Master would begin with AAA1, AAA2, AAA3… and so on

The ALLEGION chart below outlines the hierarchy of the Everest C sections.

  1. The bottom row (C134, C145, C135, C125, C124, C123, C234, C235, C245, C345) are available in a cylinder and key.
  2. The other sections (C150, C120, C100, C200, C000) are only available in keys.
  3. How to read.
    1. A C150 key will operate the C145, C135, and C125 sections.
    2. A C000 will operate all sections in bottom row.

Change Keys are single section keys. The Change Key definition is a bit misleading. A Change Key code can be used for multiple cylinders, or locks. For example, in a school Master Key System, several classrooms may be Keyed Alike. Thus, teachers’ keys might open every door in their hallway, but they won’t open the door to the principal’s office. The principal’s key, if it is a master key, will open the principal’s office and all the classrooms, janitor’s closets, etc., that are “under” it in the system. However, if the school is part of a district which has multiple schools within a single Master Key System, the principal’s key will only operate locks within a single school, while the district superintendent may have a key that allows access to not only several schools, but to every principal’s office and classroom in the district.

Keyed Alike (KA) means one key fits all KA locks, for example, front and back door locks in a home can both be opened with the same key, or every lock in an office, or classrooms in a hallway, can use the same key. Having locks Keyed Alike is very common within Master Key Systems.

If a Change Key is lost, or needs to be replaced for any other reason, it should only be replaced with the next key code, or  “combination”, from the same level it originated from. When Anderson Lock is asked to create a replacement key, the code used is marked in our code books with the date it was used to indicate it is no longer available.

Temporary entry to a door can be gained by use of the Master Key above it if the assigned key is not available. Unfortunately, some building management personnel duplicate a Master Key rather than following proper procedures and ordering the “next” Change Key. This threatens the security of the entire system.

Key Symbols

Each key in a Master Key System is stamped with letters and numbers indicating its own unique key symbol. The key symbol identifies the keys’ access level in a particular security system. Key symbols also allow key management personnel to keep a record of that key’s access permissions and track the person responsible for it.

A Master Key System increases security by allowing management personnel to assign different levels of access to different people. Cleaning staff and managers, for example, can access multiple departments and facilities with a single key, eliminating the need for heavy key rings.

Creating different levels of access with Masters and Sub-Masters keeps the Grand Master Key out of circulation for everyone but the highest-ranking officials. Restricted, or patented, keyways, which can’t be copied without authorization, significantly increase the safety of a key system. Precise key tracking is simple with restricted keys that are also consecutively numbered.

We maintain key systems by keeping track of codes. We note when a code is used, but it is the responsibility of the facility manager to distribute, and retrieve keys in a system. Specific names, and dates, should be recorded and maintained.

When Anderson Lock installs a new key system, we also supply door and key lists which identify key numbers and quantities, and the door number and name (i.e. John’s Office). All master keys are identified as well. Smaller key systems can (and should) be tracked and kept up-to-date with computer spreadsheets. Key tracking software is recommended for large multi-floor or multi-building systems.

Key management systems include door hardware, keying design, tracking and storage systems for all the various keys used throughout large facilities or campuses. This type of system also facilitates hardware maintenance, changing locks, making replacement keys or duplicates, and giving appropriate access permissions to visitors, service providers, or staff members.


10 Tips for Effectively Maintaining a Master Key System

  1. Create your own written company policies.
  2. Enforce company policies at all times.
  3. Keep records of all key symbols and consecutive numbers.
  4. Keep records of all names for key issuances.
  5. Record dates of issuance and return.
  6. Base access privileges on everyday needs, not on exceptions.
  7. Staff can allow higher level permissions when required for work purposes.
  8. Lost or stolen keys must be reported immediately.
  9. Staff is required to return keys and/or access cards when leaving the company.
  10. Only authorized staff should be allowed to have duplicate keys made.

One of the largest key cabinets Anderson Lock has supplied

Secure key cabinets and key tracking software are recommended for large multi-floor or multi-building Master Key Systems

Key symbols and numbered key tags help key management personnel keep records

A key system’s size and design determines basic key control protocols. Locking key cabinets, made of heavy-duty steel, and available in a wide variety of styles and sizes, keep keys safely stored and organized. Hooks, numbered key tags, and a lock location chart make it easy to keep keys organized.