Difference Between Rj12 and Rj14 (With Table)

RJ 12 and RJ14 are two separate models in structured cabling. RJ, which is also known as registered jack, is a connector that is particularly made and used in networking applications. The name ‘Jack’ applies to the female connector, although the standard does not alter the gender of the connector. These connectors are also related to “modular connectors. The RJ standard is originally designated for the wiring of telephone networks.

Rj12 vs Rj14 

The difference between Rj12 and RJ14 is that Rj12 is used to establish a connection between a single telephone connection, whereas RJ14 is used for two telephone lines. Rj12 is mostly used for phone systems, whereas RJ14 is used for two-line services. Rj12 works on a 6 position and 6 conductors. Meanwhile, Rj14 operates on a 6 position and 4 conductors. 

Rj12 is a 6 position 6 conductor wiring types which mean 6 points of the socket will be filled by 6 conductors or cables. Traditional home phones use RJ11, and corporate PBX working with key phones or Digital Phone Systems works with usually RJ12. In some telephones, configure 3 phone lines (3 CO lines) for an operator to respond to 3 various phone lines. Those kinds of telephones are commonly connected via RJ12 connectors.

RJ14 connector holds 6 points, of which 4 are connected. The pins are 2, 3, 4 and 5. It is applied for an attachment to two analogue telephone lines. It applies 4 wires for connection. It is utilised to join two telephones. It uses a 6P4C connector type. RJ14 looks similar to the Rj11 connector, but it includes two extra-thin copper strips, which are placed in the grooves underneath the plug.

Comparison Table Between Rj12 and Rj14

Parameters of ComparisonRj12Rj14
DefinitionRj12 or registered jack 12 is a connector jack that will join a primary telephone system with private telephone lines using a line circuit.Rj14 or registered jack 14 is mainly used for connecting double lines or two telephone lines.
UseThey are mainly to connect telephone lines.They are mainly used to connect double lines.
Works OnThey can only work on 6p6c conductors.They can only work on 6p4c conductors.
CablesThey make use of 6 cable wires when connecting.They make use of 4 cable wires when connecting.
ConductorsThey make use of 6 conductors.They make use of 4 conductors.

What is Rj12?

The full name of Rj12 is registered jack 12. It is a connection jack that joins a primary telephone system with private telephone lines by a line circuit. It is a male plug and individually combines with an ameRj12 female jack to secure the connection that is required for the combination.

The Rj12 employs a 6 positions 6 conductor connector. It comes with six slots for attachment using, and every six slots are utilised for communication. Specific RJ12 6-flat ribbon approved cables are worked for Rj12 connectors. This cord carries six thin copper cables and transfers & collects electrical beacons by the use of it.

In this standard ribbon cord, each six copper wires are colour coded. These colours include: white, black, red, green, yellow, and blue. Despite different wearing systems, the Rj12 is entirely diverse and complicated. The cable professional has to install the copper wearing method in precise order to make it operative.

The Rj12 connector was popular amongst the people in the eighties because the corporate offices in that era required telephone lines that were centralised. The Rj12 connector is used to set up the telephones in offices with a centralised wire quite easily. Even though we are in the 21st century, Rj12 connectors are used to set up intercom telephones in corporate offices to this day.

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What is Rj14?

The full name of Rj14 is registered jack 14 connectors. It comes with 6 positions in which 4 of them are placed. The pins are 2, 3, 4 and 5. It is utilised for attachment between two analogue telephone wires. It comes with 4 cables for connection. Rj14 is utilised to join two telephones. It makes use of a 6P4C connector type to get the job done. RJ14 has a six-position four-conductor (6P2C) modular jack.

RJ 14 has a similar appearance as RJ11; the only difference is that RJ14 comes with two extra-thin copper strips, which are cleverly places underneath the grooves that are in the plug. The RJ-14 is mainly used for two-line service. This type of connectors is utilised when the connection has multiple lines heading to a single phone unit. 

The difference between Rj11 and Rj14 is almost impossible to spot for someone who doesn’t know registered jacks. They come in the same size, shape, as well as format, and they both have the same amount of pins in them. The difference between the two is that Rj11 comes with only two contacts, whereas an Rj14 connector will come in 4 contacts. Rj14 is used to connect two telephone lines, whether in a corporate office or at home, but they need to be placed and installed precisely for a person to make use of them.

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Main Differences Between Rj12 and Rj14 

  1. Rj12 works on a 6 position and 6 conductor system, whereas Rj14 works on a 6 position and 4 conductors.
  2. Rj12 connectors are mainly used in telephone lines, whereas Rj14 connectors are used for two-line services. 
  3. Rj12 makes use of 6 cable wires. Meanwhile, Rj14 makes use of four cables only.
  4. Rj12 can accommodate two single telephone line, whereas Rj14 can accommodate double telephone lines.
  5. Rj12 can only work on 6p6c conductors, whereas Rj14 can only work on 6p4c conductors.


In conclusion, Rj12 and Rj14 have registered jack connectors that are used in every day to day parts of our lives. These registered jacks are useful enough and help us connect to one other because of their utilisation in telephone lines in our homes as well as our corporate offices. These registered jacks may be small, but they are still very popular and are still used in many corporate offices.

The main reason they are used is that they can easily connect two telephone lines or a single telephone line within minutes. Installing them requires precision, and this is why only a certified professional or an electrician can install them because otherwise, they won’t work.


  1. https://citeseerx.ist.psu.edu/viewdoc/download?doi=
  2. https://helda.helsinki.fi/dhanken/handle/10227/214879
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Last update on 2021-04-30 / Amazon Affiliate links / Images from Amazon Product Advertising API