The LERG is a database that can be purchased from Telcordia.
It contains information on every telephone switch in North America and which phone numbers they cover.
Most telephone companies build their routing tables from the LERG data.
New editions are published monthly.

Alternative sources of this information

• Area-Codes
• CCMI
• Local Calling Guide
• npa nxx source
• NANPA Report
• Quentin Sager Consulting
• Stuff Sofware
• Telcodata

Web Lookup Tools

• Area Code 4 All
• Area-Codes
• DSL Reports
• CCMI
• Local Calling Guide
• npa nxx source
• Quentin Sager Consulting
• TelcoData

Resources

• Telcordia LERG Documentation

See Also

• Telcordia
• NPA-NXX
• NECA