Area Code and Exchange (509) 405 in Washington
Exchange Code 405 for Area Code 509 covers the city of Kennewick, Benton County in the State of Washington. It is centered at N 46º 12' 40.48", W 119º 8' 14.04". This Exchange Code was introduced on 7 October 2016 and is designated as being used for Wireless telephones.
This Exchange covers telephone numbers ranging from (509) 405-0000 to (509) 405-9999.
Technical Information for Exchange (509) 405
NXX/Exchange Code: 405
Rate Center: KENNEWICK
Time Zone: PST
Exchange Status: Active
NXX Intro Date: 7 October 2016
CBSA Code: 28420
Number Pooling: Yes
Number Pooling in Exchange (509) 405
The initial set up of an Exchange was to have all 10,000 numbers (0000 - 9999) for a particular Rate Center allocated to the same local exhange carrier. With the advent of multiple carriers, allocating each one of them their own Exchange Code would be inefficient and soon use up the available number pools for a particular area. To counter this, some exchanges are split into blocks of 1,000 numbers, which can each be allocated to individual carriers. This cuts down on wasted numbers that aren't allocated as each carrier has a smaller pool available.Number Pooling is activated in Exchange 509-405 and the following thousand blocks are currently assigned to carriers.