Replacing a Phone Jack

Attaching color coded phone lines to telephone jack.
Attaching color coded phone lines to telephone jack.

Is it difficult to replace an existing telephone jack? Does the electricity need to be turned off to replace it? -Sylvia

Hi Sylvia,

Replacing a phone jack in not difficult and typically just requires transferring the color coded wires from the old jack to the matching terminals on the new one. While telephone lines do have 48 volts of electricity running through them, it’s usually not enough to cause a shock, though it may affect a pacemaker.

The electricity in a phone line does spike to around 90 volts when the phone rings, which can give a mild shock. To prevent this from happening, unplug the modular jack at the telephone interface box where the line runs into your house, and check to be sure the phone is dead before working on it. Another option is to take a second phone off the hook to prevent it from ringing.

Since phone lines have their own source of electricity, they remain energized even when the power is off, so flipping the breakers to your house will not make any difference. Also, never work on the phone line during a thunderstorm since lightning can travel through the wire and result in serious injury.

For more information about working on telephone lines, check out our articles on:

Good luck with your project!


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Backed by his 40-year remodeling career, Danny served as the home improvement expert for CBS’s The Early Show and The Weather Channel for more than a decade. His extensive hands-on experience and understanding of the industry make him the go-to source for all things having to do with the home – from advice on simple repairs, to complete remodels, to helping homeowners prepare their homes for extreme weather and seasons.


  1. I have a jack behind my desk that works but needed to plug in more lines i bought one of those plug ins that have three lines but plugs into the one jack thats behind my desk heres the problem the first two lines work and the last one doesnt whats going on here !1

  2. ok my question is we just moved into a house and the phone jack does not work the wires from the outside that connect to the jack are not hooked up just wondering if anyone can help me out the color of wires that are loose is light blue, orange, white/blue, white/orange? i cant figure it out for the life of me thanks… nicole

  3. I have a dual line telephone jack. The wires, from the wall, have detached. It is 2 pressure crimped, white with orange stripe. Where and how do I attach to the screws? Help…before I have to call the telephone company.

  4. My wife knocked off the telephone connector box for our upstairs phone while moving furniture. The telephone line going into the connector box was not color coded. It consisted of two wires with each one attached to a seperate terminal. The line from the telephone to the connector box was broken down to four wires being red, black, yellow and green. how can I make this work? Also, now my other phones don’t work

  5. I have a constant busy signal on my home phone line. On my jack I have a splitter. One line goes to my modem and router with the other line going to my home phone. I’ve tried two brand new phones along with a new jack but still have a busy signal on the phone line line. The modem/router line works fine. Verizon installed the phone line. Later I switched to T-mobile. Both companies cannot help me. T-mobile states that they do not send out technicians to the home and Verizon states to call T-mobile for help.
    Can you help me? I need a home phone badly.

  6. Hi, i need help badly!! Okay i have a phone jack already installed but the box that that goes over the wires is not there and the wires don’t have anything to connect them to another phone jack. the wires are already there but they dont have nothing to connect them to another phone jack. Can you please help me!!!

  7. Question: My mom’s house has had the same jacks for 50 yrs none of the phones that have been replaced seem to work well, could the jacks just be to old, should they be replaced? First I thought it was the phones but I don’t think so…

    • Jana,
      Try plugging a phone in the jack on the outside interface box and see how the quality sounds from there. If it’s good, the problem is either in the wiring, connections, or jacks.

  8. I need to replace a phone jack, but when I detached the old jack/cover-there is a tangle of wires behind he wall that don’t seem to have any rhyme or reason? There is a thick white one, and then the typical red/green/yellow. I am afraid to
    disconnect them for fear I will not be able to figure out the re-connect. HELP

  9. I replaced a telephone wall jack (bedroom), and now one of the other jacks in the house (kitchen – the only other one that was plugged in at the time) doesn’t work. I tried another phone and got the same result, and also moved the kitchen phone from the non-working jack to a different one and it worked fine, so it’s definitely the jack itself. Any thoughts on this, did I knock out the kitchen jack when I replaced the bedroom jack?

    In case it matters, my phone system is Verizon FiOS.

  10. I live in an apartment that was just remodeled on the inside. When they put up the drywall they covered all existing telephone and cable jacks. I had the cable company drill through the wall and create new ones, but I really don’t want to dish out the installation fee for a phone jack that I KNOW is there somewhere. How do I find where it was before they covered it so I can just install the jack on the inside myself? How can I tell where it is in my specific apartment from outside of my apartment?

    • Hi Barbara,
      That’s a tough one. I would start by approaching the manager of the apartment complex, since it should be there responsibility to fix it, and I imagine others there are having the same problem. If you don’t have any luck with management, here are some other things to try. If the phone jack was in a metal box, you might could find it using a stud finder. Also, check any before photos you might have taken of your apartment, see if it’s pictured, and try to estimate the distance from the floor and walls based on the size of other things in the photo. If you’ve got a general idea of where it was, the box was probably attached to a stud, so you could start from there, make a small hole in the wall, insert a small mirror with a flashlight reflect on it, or feel around in the wall for it. Your other option would be to run a new phone line.

  11. I have a stainless wall mounted phone jack plate. I don’t want to mount a wall phone but would like some type of decorative cover to slip over the top. Could you advise where I might find this product?

  12. The old phone outlet has been cut off.If the there are 4 wires (black,white,red,blue) in an older style single floor unit complex in Queensland. What coloured pair of wires would usually be used to put a single phone outlet on?

  13. My phones go dead when they try to ring, I repaced junction box for bedroom answering machine they were a little corroded . checked all wiring in basement. phones had dial tone until they tried to ring. I had my son-in-law call back he said it rung once then nothing dead agan. all phones work from interface plug. any ideas?
    Milt. P.S. I plugged into the interface box works from there.

  14. I have Fios. I am trying to replace a faulty phone jack, but when I went to unplug the phone following the guidance above, I found that I could not since the fios is all plugged in differently. I went to the fios box to see if I could unplug it there. No luck. Any ideas? Also, there seem to be the four colors on the new jack, but also a gray and blue/gray line.


  15. We have cable phone service. Recently, while remodeling my daughter’s bedroom, we unscrewed the old, unused phone jack from the wall, cut the wires from the jack, and taped them. We then installed a new blank panel, the same color as the other new outlets in the room, where the phone jack was. A couple of days later I noticed the fax and phone in my home office weren’t working, but the phone in the kitchen is fine. Since my home office and the remodeled bedroom are on the same side of the house, did we disrupt the circuit in some way? Or, is this coincidental?

  16. my problem is this.. there are 6 telephone wires that come out of the wall. The telephone jack I bought has room for 4 wires and they are different colors than the wires coming out of the wall.. how do I connect the adapter?

  17. new phone and cable jacks were installed in my house 2 yrs ago. recently i pluged a phone into a phone jack and it does not work , it says no line. i disconnected the cover from the wall only to find that the green wire is not connected because it is too short, how can i fix this problem

  18. Ok I moved n a house that don’t have no phone jacks at all. It’s gonna cost $205 just for one phone jack to b installed, that’s crazy. I’ve lived n older houses that had phone jacks. This place has zero. I don’t think there’s even a phone box either. We want to do it ourself but don’t know what to do. Please help!!

  19. I don’t have a home phone, haven’t for 7 years. Right now, I am upgrading all the outlets and jacks in the house so do I have to do anything to prevent from getting shocked or is it safe to say, the jacks have no voltage running to them. I live in a condo

  20. I just stripped the four wires to replace the jack but the green one got cut accidentally. There is no slack to strip it again. What to do?

  21. We are replacing a non working wall phone jack (45 years old) which has different wiring from the new one we just bought. The old wires are: blue with red dashes of color, red with blue dashes of color, blue with white dashes of color, and white with blue dashes of color. How do I match up these old wires to the green, red, yellow and black wires on the new jack?

  22. I have a two phone wall jack that needs to be replaced. I cannot figure out how to remove the two wires to each outlet and the mounting screw to the wall is behind the two outlets. Any help would be appreciated. Thank you!

  23. I’m moving into a condo and the wall phone jack has 2 outlets in the plate. One has a green housing around it. What is that jack for? I was going to attach a picture but you don’t have that capability.


  24. I was removing phone jacks in my house that were not being used as there were a bunch i didn’t need. well when i removed one jack in the basement simply by cutting the wires right at the jack all the lines stopped working. i never cut any main lines all right at the jacks. what is the reason and can i fix this with out adding the phone jack back?

  25. I have a wall phone I want to remove completely. I have a filter on the line, when I remove it, my other phones are static. its behind the back splash,and willnot be accessable. if I put the filter on the jack and shove it inside the wall and hope I don’t have in the future. will it work?

    • Heidi,
      It would have to be a phone jack with a standard electrical wall box. You would have to remove the phone cable, run an electrical wire to it, and replace the phone jack with an electrical outlet.

  26. I just moved into a house and after my cable people got there to install tv and internet we discovered there wasn’t a phone jack any where in the whole house. is there a way to add or turn one of the regular plugs on the wall into a wall phone jack so I can plug my internet in to it?

  27. my wires out of floor have only three i took heavy covering off back about two inches still only yellow,red and green wires, but new jack has yellow,red,gren,nd black ones how to i hooh up or do i have wrong jax thanks a lot

    • TDR,
      You might be able to splice each of the phone cable lines together using splice connectors. If not, you’ll need to run a new line from the box.

  28. I followed the telephone line from one jack to next jack (last one). The last jack was not connected, but the two cables, the same color were there, connected them. Had a telephone tester. the installation was OK. Had electricity in the last jack and in the jack I took it from. Polarity OK, but connected the phone in the last jack and no dial tone. Don’t know what I did wrong. Can you help. I live in Costa Rica. Would you email any help. Thanks

  29. I am trying to replace a late 50s-early 60s wall phone jack.
    There are only three wires coming into the house–red, green and yellow, no black; the old jack (disintegrated) and the new jack have red, green, yellow and black terminals.
    How do I route the three wires to the four terminals?
    Thank you.

  30. I have a wall plate that has the phone jack on the top and a cable screw on the bottom. Just to be clear, the bottom cable screw protrudes from the jack. The wall plate is ABOUT 4 3/4inches by 2 1/2 inches. The phone jack does not work. How do I replace the phone jack? I can’t find a similar looking jack online. I assume the cable jack works but it is not an issue.

  31. I have an older house and only one phone jack worked. I recently had the floors replaced in that room and they knocked my phone jack off and I can’t even see the wires. My guess is they were trying to hide it anyway. How do I find the wires or run new ones to connect a new jack? Thanks in advance!

  32. I have a second phone line into my house which is no longer being used. I am in the middle of renovating the room it is positioned in and want to take the white box out. Not bothered about the bt cable to the house staying there. How would I go about this and is there any chance of me getting electricuted? Also would I have to do something with the wires coming into the house or will they be fine just as they are?!

  33. My walljack does not work. Are all wall jacks the same? Different plugins? Need to replace it, but need to know if I am buying the right one. Can you assist? Thanks

  34. I just bought a new modular telephone jack it has four screws with yellow, black, red, and green wires. The phone line has the following colors red, green, blue, white with blue stripe, white with red stripe, and white with green stripe. Which ones do I connect to the modular jack? Help?

  35. Hi! I cut the wiring to get rid of the phone jack but found out later I need it for internet. There are three wires coming out, do I use all three?

  36. My problem is that the only down stairs phone jack is very loose and doesn’t hold a steady connection to the internet. I constantly have to reset the wireless router almost every other day due to the lost connection. I just need to know how easy it is to install a new phone jack and around how much, because it is needed asap. So i have a better internet connection and higher Mbps.

  37. Just need a to change out my downstairs phone jack so am wondering where to get them, how much and wanted to see if anyone knew exactly how to put them in and maybe give a tutorial in which wires go where. It needs to be done asapo please!

    Terry R Asbury Jr

  38. Also just want to know u guys have a video in how to do so, so i can learn by using the same set up procedure and not have to reset the internet so often. And keep a steady internet connection.

  39. Went to replace jack. Colors don’t match. Wires in wall are solid bue, white w/blue stripe, orange , white w/orange stripe . Wall jack has red green yellow and black. New jack the yellow and black are reversed. Do I flip flop wires to match

  40. Went to replace jack. Colors don’t match. Wires in wall are solid bue, white w/blue stripe, orange , white w/orange stripe . Wall jack has red green yellow and black. New jack the yellow and black are reversed. Do I flip flop wires to match the colors .

  41. I have 2 other working jacks in the house. Can I use one of them to replace the broken one in the kitchen, instead of buying a new one?

    Thanks – AG

  42. How do I get my main box connected to put on my tv phone and internet back on once it goes off. What should it look like for it to be right


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