The international phone system rejects the area code 547 since it is not currently assigned to any place in the globe. All area codes between 545 and 550 are currently unassigned and invalid as of September 2014.
To get around caller identification systems, phone calls and texts that appear to be from this area code are actually spoofs. Spoofing is the practise of transmitting bogus information over the phone line to hide the true identity of the caller or text message sender.
This can be accomplished by signing into a third-party service or by utilising software that transmits calls or texts from a different number from the one actually sending them. By using an incorrect area code, like 547, the call cannot accidentally be linked to any active phone numbers.