Products affected: DM300C™, DM400C™, DM450C™, DM475™
A dialing prefix, such as '9', may be required to connect to an outside line, depending on your phone system configuration. Follow these steps to change your dialing prefix:
- Press Menu.
- Press Page Down twice.
- Select Data Center Options.
- Select Phone Settings.
- Select Dialing Prefix.
- Enter the required prefix and select Accept.
- Press Home to return to the home screen.
UPDATED: March 12, 2019