Need a list of all the working NXX codes (prefixes) in your area?
See the North American Numbering Plan Administrator's website:

http://www.nanpa.com/

Select NUMBER ASSIGNMENTS from the left side of the screen

Select Central Office Codes from the NUMBER ASSIGNMENTS screen

Select CENTRAL OFFICE CODE ASSIGNMENTS from the Central Office Codes screen

Locate the file by state abbreviation (each file contains several states)

Select "cnutlzd.zip" to get a complete list of all the codes in use

Select "cnavail.zip" to get a complete list of all codes available for assignment


Need a complete list of all the NXX code (prefix) changes from last month?
See Telcordia's Traffic Routing Administration webpage:

http://www.trainfo.com/products_services/tra/index.html

Select NNAG (NPA/NXX Activity Guide) from the left side of the screen

Follow the download instructions


Need more information about new and existing NPAs (Area Codes)?
See the North American Numbering Plan Administrator's website:

http://www.nanpa.com/

Select NUMBER ASSIGNMENTS from the left side of the screen

Select Area Codes from the NUMBER ASSIGNMENTS screen

You will be given several different options for area code information