These settings are also available in the first-time setup wizard. As you change your dial plan, the example numbers in Control Hub update to show these changes.

Before you begin

If you want to decrease the extension length in your organization, there are few things you need to do to prepare for that change:

  • Make sure extensions aren't assigned to users and features. You can go to Cisco Webex Control Hub and check what extensions are used under Services > Call > Numbers.

  • Temporarily remove the Webex Calling (formerly Spark Call) license assignment for your users.

  • Remove all Webex Calling (formerly Spark Call) features, such as call park, auto attendants, hunt groups, and pickup groups.


From the customer view in, go to Services, and then choose Call > Settings.


Configure your internal dialing preferences:

  • Internal Extension Range—The maximum is 10000 extensions for each range.
  • Routing Prefix—This setting only applies to multisite dialing. Until multiple locations and tiered dialing are supported, choose None for this setting. For a flat dial plan, you don't require a routing prefix.
  • Extension Length—You can enter 3–10 digits and the default is 3. When you increase the length, you're prompted to enter a prefix for existing extensions. When you decrease the extension after you've assigned some extensions, your existing extension ranges are deleted and you have to enter a new extension range for the new length.
    • You can only decrease the length if you haven't assigned any extensions to users or other features.

    • You can only increase the length if your voicemail is disabled.


    After you increase your extension length, existing speed dials to internal extensions are not automatically updated.


Configure your external dialing preferences:

  • Outbound Dial Digit—The number that users must dial to reach an outside line. The default is 9, and the value can be None if you don't require this dialing habit.
  • Dialing Preferences—Choose how PSTN dialing is handled (full phone number or simplified local dialing). If you choose simplified, you can add a prepended area code if you want the code included by default and don't require users to dial it. You can also remove the leading 1, if necessary.