Sign in to Control Hub, go to Services > Calling > Service Settings, and then scroll to Internal Dialing.

Configure the following optional dialing preferences, as needed:

• Location Routing Prefix Length—If you've got multiple locations, we recommend this setting. You can enter a length of 1-7 digits. If you have multiple locations with the same extension, users must dial a prefix when Calling between locations. For example, if you have multiple stores, all with the extension 1000, you can configure a routing prefix for each store. If one store has a prefix of 888, you'd dial 8881000 to reach that store.

  • Routing prefix lengths include the steering digit. For example, if you set the routing prefix length to four, you can use only three digits to specify the site.

  • If you assign a routing prefix to a location, all appearances of extensions assigned to that location include the routing prefix in front of the extension number. For example, 888-1000 (routing prefix-extension).

• Steering Digit in Routing Prefix—Choose the number to set as the first digit of every routing prefix.
• Internal Extension Length—You can enter 2-10 digits and the default is 2.

  After you increase your extension length, existing speed dials to internal extensions aren’t automatically updated.

• Allow extension dialing between locations—Allows you to customize the extension dialing between locations based on your organization's requirements.

  • Enable the toggle if your organization doesn’t have duplicate extensions across all its locations.

    By default, the toggle is enabled.

  • Disable the toggle if your organization has the same extension in different locations. When the toggle is disabled and the caller dials the extension, the call is routed to a user with a matching extension in the same location as the caller. The caller must dial the Enterprise Significant Number (location routing prefix + extension) to reach an extension in other locations.

Specify internal dialing for specific locations. Go to Management > Locations, select a location from the list, and click Calling. Scroll to Dialing, and then change internal dialing as needed:

• Internal Dialing—Specify the routing prefix that users from one location need to dial to contact someone at the other location. The routing prefix of each location must be unique. We recommend that the prefix length matches the length set at the organization level but it must be 1–7 digits long.

Specify external dialing for specific locations. Go to Management > Locations, select a location from the list, and click Calling. Scroll to Dialing, and then change external dialing as needed:

• External Dialing—You can choose an outbound dial digit that users must dial to reach an outside line. The default is None and you can leave it if you don't require this dialing habit. If you do decide to use this feature, we recommend that you use a different number from your organization's steering digit.

  Users can include the outbound dial digit when making external calls to mimic how they dialed on legacy systems. However, all users can still make external calls without the outbound dial digit.

• Optionally, you can Enforce dialing the outbound dial digit of this location, ensuring that the user must use the outbound dial digit set by the admin to place external calls.

  • You can dial emergency calls with or without the outbound dial digit, on enabling this feature. Once enabled, any external destination numbers such as those used for call forwarding will no longer work if an outbound dial digit isn’t included.

  • If an extension is the same as the national number, then the extension takes precedence over the national number. Hence, we recommend that you enable the outbound dial digit.

  • We highly recommend using the E.164 numbering format for incoming and outgoing PSTN calls.

  • If the national number begins with the same digit as the outbound dial digit, the system removes the initial digit. You must add the outbound dial digit before the rest of the national number to complete the call successfully.