According to published directories, 723 is not a valid area code as of 2014. Therefore, telephone calls appearing to originate from within that area code are generally considered to be spoofed or faked.
Name That Number suggests that calls from the 723 area code are often telemarketers or bill collectors attempting to mask their true telephone number in an effort to trick the recipient into answering the call. Hackers can also spoof telephone numbers in an attempt to gain information by means of deception. When in doubt about the legitimacy of a number, it is wise for the recipient to disregard the call, especially if the caller asks for sensitive information.