Some office environments require you to dial a number in order to get an outside line. For example, you may need to dial a 9 or another number sequence before you can place a call. CapTel 2400iBT lets you add a dialing prefix, then will dial it for you automatically for every call placed from your Contact list, or when using the Speed Dial, Call History, or Answering Machine history. If you dial the phone number directly, you will need to enter the Dialing Prefix at the time you dial. The default setting is no dialing prefix.
Settings → General Settings → Advanced Settings