Area codes 847 and 224

Area codes 847 and 224 are telephone area codes in the North American Numbering Plan (NANP) for the U.S. state of Illinois.

The numbering plan area (NPA) comprises the northeastern part of Illinois and many northern suburbs of Chicago.

Area code 847 was involved in the first trial of telephone number pooling in the United States in June 1998, to avert central office code exhaustion in the numbering plan area.

[1] Nevertheless, within only five years, 847 was already close to exhaustion from the rapid growth in telecommunication services in the Chicago suburbs and the proliferation of cell phones and pagers.

This required ten-digit dialing in all affected communities.