Using the tel Protocol with 3CXPhone for Windows

What is the tel Protocol?

The easiest way to define what the tel protocol is, is to simply think of it as a link that communicates a telephone number. That means that when you click on a tel link the tel protocol will try to pass the number to an application that can make a call. A tel link takes the form of: tel: +35722444032.

The first part of the URI defines the protocol and the second part defines the number to be dialled (which can be in either local or international format). The 3CXPhone client now integrates with the tel protocol to provide the users with click to call functionality.

Using 3CXPhone with tel Protocol

To start making calls using the tel protocol, install the 3CXPhone for Windows client on your machine, and then follow these steps:
To use click to call functionality first find a web page with Tel Links in this case we will use

  1. Find a web page that has tel links. In this example we will use Click on the tel link.
    After clicking on the Tel links you will receive a request to launch an external application to handle it. Select 'Launch Application' to use 3CXPhone for Windows
  2. A popup will appear with the title “External Protocol Request” asking you to launch the registered application (3CXPhone for Windows) to handle this tel link.
  3. Select “Launch Application” to use 3CXPhone for Windows Client.
    After clicking Launch Application the 3CXPhone for Windows will maximize and dial the number.
  4. 3CXPhone for Windows will maximize and and make the call to the number contained in the tel link.

Associate the tel Protocol with 3CXPhone

3CXPhone for Windows will register as the handler for tel protocol during installation automatically. If you discover that another application has registered to handle the tel links at a later stage you can change that registration back to 3CXPhone:

To restore Tel  protocol handling back to 3CXPhone for Windows open the Windows Control Panel and click on 'Default Programs'

  1. Open the Windows Control Panel and click on “Default Programs“.

    After selecting Default Programs click on 'Associate a file type or protocol with a program' button
  2. Select “Associate a file type or protocol with a program” from the default programs list.

    Scroll down the association list to protocols, click on 'Tel' and press 'Change Program'
  3. Scroll down to the bottom of the list in the protocols section, find TEL, select it and click “Change program“.

    Select 3CXPhone for Windows from the list of programs to set it as the default handler for Tel links
  4. Select “3CXPhone for Windows” from the list of programs. Click on the close button to close the “Set associations” panel.

You have now set 3CXPhone for Windows to be the default handler for tel links.