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If you want help with LineLink setup, voicemail and call forwarding services, or calling & connection issues, we have you covered.


Set up a LineLink

Get to know your T-Mobile LineLink device


Set up your LineLink service

Setup steps

First, make sure:

  Your E911 address is added and updated on the account.

  Other devices on your home/office Internet can stream video and audio. If not, contact your ISP.

When you're ready to set up:

  1. Insert the provided SIM card into the T-Mobile LineLink with the metal facing up, cut corner inserted first.
    1. Make sure you have a T-Mobile Micro-SIM card.
      • If you have the SIM kit, pop out the middle-sized cutout.
      • If you popped out the smallest SIM cutout, push out the middle-size adapter and put the SIM in. Then insert it into the device.
      • If you have problems with the SIM card or ti gets stuck, stop by a retail store for help.
    2. Find the SIM slot on the LineLink device. (See the device image​ above.)
    3. Align the SIM card metal side up and the cut corner facing the LineLink device.

    4. Insert the SIM card into the SIM slot. The SIM slot is spring loaded, so the card clicks into place.
  2. Plug in the provided Ethernet cable:
    • One end goes into the LAN port on the LineLink device.
    • Other end goes into an empty LAN port on the back of your Internet router.
  3. Plug the provided USB cable into the T-Mobile LineLink and into the power adapter.
  4. Connect the home phone to the LineLink phone port.
  5. Wait 3 minutes for the device to set up.
  6. When the Phone LED is blue and Power LED is solid green, it means the LineLink is ready for use. If they don't turn blue/green, see Light indicators.
  7. Pick up the home phone and listen for the welcome message: "Congratulations, your T-Mobile LineLink is now ready to be used."
  8. Dial 1-2-3 or the LineLink phone number to start your voicemail setup.
Start guide (Printable)

You can also download the LineLink Quick Start Guide (English & Spanish) at the bottom of this page for reference.


  • The Phone LED flashes blue when you've received a new voicemail message.
  • To check voicemail, call 1-2-3 from your LineLink phone or call your own phone number.
  • If you need help with the voicemail system, see .

Call forwarding

Forwarding all calls (CFU)

  • To activate, dial *72 + mobile number. Example: *72 (206) 111-1111.
  • To deactivate, dial *73.

Forwarding calls if you don't answer (CFNR)

  • To activate, dial *42DN.
  • To deactivate, dial *93.

Also see more LineLink short codes.

Reset the device to factory settings

  1. Insert a paper clip or other small tool in the RESET hole.

  2. Press and hold the Reset button for 10 seconds.
  3. Release the Reset button. The device is now restored to factory settings.

Light indicators

Power Phone Internet Light pattern description & help
Your LineLink is set up successfully. Check that you hear a dial tone after the welcome message, and you're good to go.

You have a new voicemail! A stuttering tone will also play when you pick up the phone to let you know there's voicemail.

Check your voicemail. After listening to the voicemail, the blue phone LED will go back to solid and the stutter tone will no longer play.

You have not yet provided an E911 address  for emergency services. This is required for your safety, so emergency services can find your location.

Add your E911 address to connect to the service.

Your T-Mobile SIM card might not be properly activated.

Contact us for assistance checking into this.

Your LineLink device can't connect to the Internet or T-Mobile network.

Error you may hear

"We seem to be having issues connecting to the T-Mobile network. Please ensure your LineLink is properly connected to a data port and reboot your device."

  1. Check that your LineLink is properly connected to the high-speed Internet connection.
  2. Make sure other devices can connect to the high-speed Internet connection and open web pages.
  3. If you continue having SIM issues, follow the rest of the steps in Troubleshoot issues with your LineLink.

Your LineLink encountered an error during registration.

Errors you may hear

  • "We seem to be having issues detecting your T-Mobile SIM card. Ensure your SIM card is properly inserted into your LineLink and reboot your device."
  • "There seems to be an issue with the activation on this SIM card. Please ensure you have an active T-Mobile line activated on this SIM."
  1. Remove and re-insert the SIM card correctly. If the SIM card gets stuck, stop by a retail store for help.
  2. Unplug the power from the LineLink device. Wait a few seconds, and reconnect it.
  3. If you continue having SIM issues, please contact us for assistance checking into this.

Troubleshoot issues with your LineLink

Before you dive too deep into troubleshooting, make sure of the following:

  Other devices on your home/office Internet can stream video and audio. If not, contact your ISP.

  You completed the setup process​.

  The SIM card is inserted correctly, following the setup steps.

  The phone cable is securely plugged into both your home phone and the LineLink device.

  The Ethernet cable is securely plugged into both your router and LineLink device.

If your device meets the criteria above and you still have connection issues, poor call quality, or other issues, proceed with the steps:

  1. Check the Light indicators for help with your particular issue. After that, move on to step 2.
  2. Test your internet connection to make sure your it meets requirements.
    1. On a computer that's connected the same router as the LineLink, open
    2. Select Go to test your internet connection.
    3. Make sure your results meet the following requirements for service:
      • Download: 2 Mbps (or more)
      • Upload: 2 Mbps (or more)
      • Ping: 200 ms (or lower)
      • Satellite and cellular Internet don't work with LineLink.
  3. Did your speed test results pass the requirements?
    • No, one or more numbers did not pass

      Contact your Internet provider (ISP) or local IT. Tell them you are using a VOIP service and need to check your connection and speeds. You'll need to pass the tests before LineLink will work.

      T-Mobile is unable to assist with your home or office Internet service.

    • Yes, speeds and ping passed requirements

      Your Internet speeds are ok.

      If your LineLink Phone LED light is orange, you'll need to look into the Internet settings below.

      Check the the following ports are open on your router. If you need assistance, refer to your Internet provider (ISP), local IT, or router user manual.

      • 500 UDP
      • 4500 UDP
      • 5061 TCP/UDP
      • 443 TCP
      • 993 TCP

      Business consumers, ensure the following IPv4 address blocks are whitelisted:

      • address block
        • Port 500, UDP, IPsec - IKE : Authentication [WFC 2.0]
        • Port 4500, UDP, IPsec - NAT traversal : Encrypted voice traffic [WFC  2.0]
        • Port 5061, TCP/UDP, SIP/TLS : Encrypted SIP [WFC 1.0]
      • address block
        • Port 443, TCP, HTTPS : Used for handset authentication [WFC 1.0]
        • Port 993, TCP, IMAP/SSL : Visual Voicemail [WFC 1.0]

      T-Mobile is unable to set up your home or office Internet service.

  4. Plug the LineLink device into a different LAN port on the back of the router.
  5. Unplug the power cables from the LineLink device, the router, and the modem to turn them off.
  6. Plug in the modem first. Plug in the router after the modem shows it's connected to the Internet.
  7. After the router has started and connected, plug in the LineLink device.
  8. Try a different home phone and a different phone cable (RJ11), if possible.
  9. If you still have problems after these steps, contact us.


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