ESN (Emergency Service Number)

ESN (Emergency Service Number) is a 3-5 digit number that represents one or more ESZs (Emergency Service Zone), stored as a 3-5 character numeric string in a GIS database. An ESN is defined as one of two types: Administrative ESN and Routing ESN.

NENA 57-503, NENA Procedures for Notification of ERDB and VPC Operators of ESN Changes by 9-1-1 Administrator Operations Information Document