The North American Numbering Plan (NANP) is a telephone numbering system that was established in 1947 to simplify and standardize the way phone numbers are assigned in the United States, Canada, and several other territories. It uses a three-digit area code followed by a seven-digit local number, allowing for efficient call routing and management across different regions. Under the NANP, each area code corresponds to a specific geographic region, making it easier for callers to identify where a call is being placed. The plan also includes provisions for toll-free numbers and special services, ensuring that communication remains accessible and organized across the North American continent.