LRN (Location Routing Number)

This glossary was last updated on January 22, 2024.

What is an LRN?

LRN means Location Routing Number and serves as identification for telephone switches when routing phone calls through the U.S. PSTN (public switched telephone network). 

LRN has the format of a 10-digit North American Numbering Plan (NANP) phone number, and this is required for local number portability (LNP).

How LRNs function

LRNs were created to provide local number portability by allowing numbers to route successfully when moved between carriers. Calls to ported or pooled numbers are routed based on the NPA-NXX of the number’s associated LRN. If your number is transferred to another provider, the current telephone number can be retained and only the LRN needs to be changed.

Each carrier has at least one LRN per Local Access and Transport Area. 

When telephone numbers are ported over from another carrier, Bandwidth assigns an LRN to the number to ensure routing is correct.

Terms related to LRN

• Number Planning Area (NPA) and NXX
• Local Access and Transport Area (LATA)
• Local Exchange Routing Guide (LERG)