Dial the main office number.
Wait for the automated attendant or operator prompt.
Enter the extension number using the keypad.
If prompted, press the required key (often “#” or “send”) to confirm.
If there’s no prompt, wait a few seconds for the line to connect.
If you hear a busy signal or incorrect extension message, hang up and redial.
If you reach the wrong person, ask the operator to transfer you to the correct extension.
If you get voicemail, follow the prompts to leave a message for the extension.
If calling from a mobile phone, include any required access code (such as country/area code) before the main number.