On August 1, 2015 the USPS starts enforcing changes to the Labeling List.
The USPS changed the Labeling List data in response to consolidation of processing facilities to improve efficiencies and reduce costs. Changes also become necessary when shifts in population, mail volumes, and staffing affect the boundaries of a service area.
You should note that the USPS used to make this type of label data update quarterly. It now makes them monthly. Frequent updating means that a Label List is effective for about 60 days.
The Labeling Lists affected are:
The Labeling Lists are located on the Postal Explorer website under the “Additional Links” tab. This directs you to the Facility Access and Shipment Tracking Systems (FAST) website; from there you can choose Resources, then Label Lists File Download, then Label List Files.
For more information go to USPS Labeling Lists.