| Alternate Billing Exchange Code |
| Access Customer Name Abbreviation |
| Administrative Operating Company Number. The term "AOCN" also refers to the company that updates rating and routing information associated with central office code assignments. |
| Automatic Number Identification |
| American National Standards Institute |
| Alliance for Telecommunications Industry Solutions (www.atis.org) |
| Business Integrated Routing and Rating System |
| Carrier Identification Code |
| Common Interest Group on Rating and Routing |
| Competitive Local Exchange Carrier |
| COMMON LANGUAGE® Location Identification |
| Central Location ON-line Entry System |
| Central Office |
| Central Office Code Assignment Guidelines |
| Emergency Notification |
| Easily recognizable (area) code |
| Federal Communications Commission |
| Feature Group A, B, C, D |
| Foreign NPA |
| FCC Registration Number |
| Home NPA |
| Incumbent Local Exchange Carrier |
| Industry Numbering Committee |
| Initial Planning Document |
| Interexchange Carrier |
| Local Access and Transport Area |
| Local Exchange Carrier |
| Line Information Data Base |
| Local Number Portability |
| Location Routing Number |
| Metropolitan Statistical Area |
| Months to Exhaust |
| Mobile Telephone Switching Office |
| North American Numbering Council |
| North American Numbering Plan |
| North American Numbering Plan Administration |
| National Association of Regulatory Utility Commissions |
| NANP Administration System |
| Number Administration Service Center (Toll-Free 800/866/877/888 database) |
| Next Generation Interconnection Interoperability Forum |
| Number Oversight Working Group, a subgroup of the NANC |
| Numbering Plan Area (Area Code) |
| Number Portability Administration Center |
| Number Resource Optimization |
| Network Rating and Routing Information Committee |
| Numbering Resource Utilization Forecast |
| The format of an NPA code or a central office code (N=2-9, X=0-9) |
| Ordering and Billing Forum |
| Operating Company Number |
| Pooling Administrator |
| Personal Communications Service |
| Public Safety Answering Point |
| Public Service Commission |
| Public Switched Telephone Network |
| Public Utilities Commission |
| Rate Area |
| Rate Center |
| Rate Center Consolidation |
| Service Access Code |
| Service Provider |
| Signaling Transfer Point |
| Telephone Number |
| Terminating Point Master |
| Telecom Routing Administration |
| Vertical & Horizontal (Coordinates) |
| Voice over Internet Protocol |
| Vertical Service Code |
