Workbooks can be configured to work with a variety of telephone systems.

Typically your browser will respond to one or more of the links below - you can try them out from this page.  Configure Workbooks - in your Preferences - to use one of the styles below:

• callto:+448456505050
  Enter callto:@number@ in your Preferences. By default Workbooks is setup to use this format because it is the most widely-used.
• tel:+448456505050
  Enter tel:@number@ in your Preferences. This is the official "standard" but is less widely used.
• sip:+448456505050
  Enter sip:@number@ in your Preferences. Some telephone systems and applications use this instead.

You may have to do some setup on your PC to cause your browser to do the right thing when presented with these links.