Editing Overlay complex (section)

{{Short description|American telephone numbering plan}}
{{more citations needed|date=June 2020}}
{{Use mdy dates|date=November 2018}}
{{Use American English|date=January 2018}}

In [[telecommunication]]s, an area code '''overlay complex''' is a [[telephone numbering plan]] that assigns multiple [[area code]]s to the same geographic [[numbering plan area]] (NPA). Area code overlays are implemented in territories of the [[North American Numbering Plan]] (NANP) to mitigate exhaustion of central office codes in growth areas. The method has been in use since 1992, and has been the exclusive method of area code relief since 2007.