Abstract: A fraud detection apparatus receives a telephone call including area and national numbers from a switch and determines when the telephone call is fraudulent. The fraud detection apparatus includes a switching processor capable of receiving the area code and national numbers from a local telephone switch. The switching processor may also have the capability of storing potential fraudulent call information, such as area codes, billing numbers and domestic or international directory numbers. The processor determines the telephone call to be fraudulent when any or a combination of the above numbers matches one of the potential fraudulent numbers stored in its memory.