USPS Postal Zones are how the United States Postal Service determines the distance between an origin and destination address. These zones range from 1-9. Zone 1 is a local shipment and Zone 9 is the furthest possible distance for a domestic shipment.
At this time, ShipStation only supports displaying USPS Zones. We are not able to display zone information from any other carrier, like FedEx. Even though zones are USPS-specific, the information can be helpful when using other carriers, since they're representative of the distance between the ship from and destination address.
The way to take advantage of these zones is to use them as the criteria for automation rules. When making an automation rule based on destination address, instead of using the city name or postal code, it is far more efficient to use the destination address's postal zone. Here is an example of how the criteria could look:
Where to find Zones
If you would like to get the best understanding of which postal codes are in which Zone, the USPS has a great tool to show the zone relationship between a postal code and all others based on their first three digits. For more info, see the USPS Domestic Zone chart.
To view these zones on an order on the orders page, select Zones from the Columns drop-down in the upper righthand side of the Orders Page.
You will then be able to view the zones on the orders page.