Residential Telecommunications: Jacks and Plugs

This topic contains information for readers interested in how telephone jacks, plugs, and cables are wired.

Note: The information presented here is for illustrative purposes only. Use it at your own risk. Read and understand the Disclaimer and Terms and Conditions of Use pages before proceeding.

Connector Colours

The following table shows some common pin number to colour code assignments for connectors used in telephone circuits. For example, if a 6 position 4 conductor telephone jack has cable connection points labelled with red and green colours they will probably connect to the pins at positions 3 and 4 respectively in the jack's outlet socket.

Notes

The following notes apply to both tables on this page.

When no colour is shown, the position is left empty.
When one scheme appears it is the striped colour scheme.
When two colour schemes appear the top one is a striped colour scheme and the bottom one is a solid colour scheme.
For jacks, position numbers are assigned looking into the jack with the locking tab down and position 1 at the left.
For plugs, position numbers are assigned looking at the conductor side of the plug, i.e. with the locking tab on the bottom, and position 1 at the left.
6-position jacks and plugs are frequently, and incorrectly, referred to as RJ11 connectors.
8-position jacks and plugs are frequently, and incorrectly, referred to as RJ45 connectors (see
Wikipedia - "RJ45" naming confusion).

Connector Colour Codes
Standard Name	Connector	Pin Configuration								Notes
	Total Positions + Total Conductors	Connector Position #
		Pin Colour - Text
		Pin Colour - Image
RJ11	6P2C		1	2	3	4	5	6
					Blue	White + Blue
						/ / / /
					Red	Green

RJ14	6P4C		1	2	3	4	5	6
				White + Orange	Blue	White + Blue	Orange
				/ / / /		/ / / /
				Black	Red	Green	Yellow

RJ25	6P6C		1	2	3	4	5	6
			White + Green	White + Orange	Blue	White + Blue	Orange	Green
			/ / / /	/ / / /		/ / / /
RJ61	8P8C	1	2	3	4	5	6	7	8	See Using 8 Position Jacks for Telephone Lines for important warnings. Rarely used in residential wiring. Shown for historical reference only. This is the official USOC standard registered by the FCC. Some older systems use a standard, unofficially called "USOC", but the assignments of pins 1 and 8 are reversed.
		White + Brown	White + Green	White + Orange	Blue	White + Blue	Orange	Green	Brown
		/ / / /	/ / / /	/ / / /		/ / / /
T568A	8P8C	1	2	3	4	5	6	7	8	See Using 8 Position Jacks for Telephone Lines for important warnings.
		White + Green	Green	White + Orange	Blue	White + Blue	Orange	White + Brown	Brown
		/ / / /		/ / / /		/ / / /		/ / / /

Cable Connections

This table shows some common configurations for connecting the individual wires in a cable to the individual pin positions in a connector. Note the only colours shown are those for cable conductors. To match a connector pin number to a connector pin colour use the table above.

Cable to Pin Connections
Desc. Standard Name	Connector	Connections								Notes
L1=Line 1 L2=Line 2 L3=Line 3 L4=Line 4	Total Positions + Total Conductors	Connector Position #
		Supply Cable Conductor Colour - Text
		Supply Cable Conductor Colour - Image
		Tip/Ring + Pair #
Notes some modern phone equipment has a polarity guard feature to protect it from wiring where the Tip and Ring signals are accidentally reversed.
6 Position Jacks - One Telephone Line
L1 RJ11	6P2C or 6P4C		1	2	3	4	5	6		Phone equipment sees only Line 1.
					Blue	White + Blue
						/ / / /
					Red	Green

					R1	T1
L2	6P2C or 6P4C		1	2	3	4	5	6		Phone equipment sees only Line 2.
					Orange	White + Orange
						/ / / /
					Yellow	Black

					R2	T2
L3	6P2C or 6P4C		1	2	3	4	5	6		Phone equipment sees only Line 3.
					Green	White + Green
						/ / / /
					R3	T3
L4	6P2C or 6P4C		1	2	3	4	5	6		Phone equipment sees only Line 4.
					Brown	White + Brown
						/ / / /
					R4	T4
6 Position Jacks - For up to Two Phone Lines
L1+L2 RJ14	6P4C		1	2	3	4	5	6		Two Line phone equipment sees Line 1 as its primary line and Line 2 as its secondary line. Single line phone equipment sees only Line 1. It requires an external splitter at the jack end to see only Line 2.
				White + Orange	Blue	White + Blue	Orange
				/ / / /		/ / / /
				Black	Red	Green	Yellow

				T2	R1	T1	R2
L2+L1	6P4C		1	2	3	4	5	6		Two Line phone equipment will see Line 2 as its primary line and Line 1 as its secondary line. Single line phone equipment sees only Line 2. It requires an external splitter at the jack end to see only Line 1.
				White + Blue	Orange	White + Orange	Blue
				/ / / /		/ / / /
				Green	Yellow	Black	Red

				T1	R2	T2	R1
L3+L4	6P4C		1	2	3	4	5	6		Two Line phone equipment sees Line 3 as its primary line and Line 4 as its secondary line. Single line phone equipment sees only Line 3. It requires an external splitter at the jack end to see only Line 4.
				White + Brown	Green	White + Green	Brown
				/ / / /		/ / / /
				T4	R3	T3	R4
L4+L3	6P4C		1	2	3	4	5	6		Two Line phone equipment will see Line 4 as its primary line and Line 3 as its secondary line. Single line phone equipment sees only Line 4. It requires an external splitter at the jack end to see only Line 3.
				White + Green	Brown	White + Brown	Green
				/ / / /		/ / / /
				T3	R4	T4	R3
6 Position Jacks - For up to Three Phone Lines
L1+L2+L3 RJ25	6P6C		1	2	3	4	5	6		Three line phone equipment sees Lines 1, 2, and 3 as its primary, secondary, and tertiary lines respectively. Two Line phone equipment sees only Line 1 as its primary line and Line 2 as its secondary line. Single line phone equipment sees only Line 1. It requires an external splitter at the jack end to see only Line 2 or Line 3.
			White + Green	White + Orange	Blue	White + Blue	Orange	Green
			/ / / /	/ / / /		/ / / /
			T3	T2	R1	T1	R2	R3
8 Position Jacks - For up to Four Phone Lines (USOC)
L1+L2+L3+L4 RJ61	8P8C	1	2	3	4	5	6	7	8	See Using 8 Position Jacks for Telephone Lines for important warnings. Rarely used in residential wiring. Shown for historical reference only.
		White + Brown	White + Green	White + Orange	Blue	White + Blue	Orange	Green	Brown
		/ / / /	/ / / /	/ / / /		/ / / /
		T4	T3	T2	R1	T1	R2	R3	R4
8 Position Jacks and Plugs - For up to Four Phone Lines (ANSI/TIA/EIA-570-B Residential Telecommunications Cabling Standards)
T568A	8P8C	1	2	3	4	5	6	7	8	See Using 8 Position Jacks for Telephone Lines for important warnings. Three line phone equipment wired for R61 will not see Line 3 on this jack. Two Line phone equipment sees Line 1 as its primary line and Line 2 as its secondary line. Single line phone equipment sees only Line 1. It requires an external splitter at the jack end to see only Lines 2, 3, or 4.
		White + Green	Green	White + Orange	Blue	White + Blue	Orange	White + Brown	Brown
		/ / / /		/ / / /		/ / / /		/ / / /
		T3	R3	T2	R1	T1	R2	T4	R4
Telephone Line Cable - For up to Two Phone Lines (for attaching phone equipment to wall jacks)
End 1	6P4C		1	2	3	4	5	6		Same assignments as RJ14.
				Black	Red	Green	Yellow

				T2	R1	T1	R2
End 2	6P4C		1	2	3	4	5	6		Note that assignments are a mirror image of End 1 (aka "frogged").
				Yellow	Green	Red	Black

				R2	T1	R1	T2
L2 to L1 Telephone Line Cable - for attaching phone equipment to wall jacks - acts like an L1+L2 to L2 splitter - uses two conductor cable - I haven't tested this configuration - this is not something I've seen or built, theoretically it might work though
L2 End (attaches to Jack)	6P4C		1	2	3	4	5	6		This end must plug into the wall/baseboard jack. Each end should be clearly labelled to prevent incorrect use.
				White + Blue			Blue
				/ / / /
				Green			Red

				T2			R2
L1 End (attaches to Telephone)	6P4C		1	2	3	4	5	6		This end must plug into the telephone.
					White + Blue	Blue
					/ / / /
					Green	Red

					T2	R2
Handset Cables (for connecting telephone handsets to their base; DOES NOT APPLY TO ALL MANUFACTURERS)
End 1	4P4C			1	2	3	4			Incorrectly known as "RJ9", "RJ10", or "RJ22". Note that colours are in the same order as RJ14. There is no single standard for these connections. This is a sample of one configuration found on some handsets. Your phone's configuration may vary.
				Black	Red	Green	Yellow

End 2	4P4C			1	2	3	4			Note that assignments are a mirror image of End 1 (aka "frogged"). There is no single standard for these connections. This is a sample of one configuration found on some handsets. Your phone's configuration may vary.
				Yellow	Green	Red	Black

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