New Castle County Delaware is covered by a total of 54 ZIP Codes. There are 2 ZIP Codes in New Castle County that extend into adjacent counties ( and Kent County). Of the ZIP codes within or partially within New Castle County there are 24 Standard ZIP Codes, 17 Unique ZIP Codes and 12 PO Box ZIP Codes.
Click on the ZIP Codes in the interactive map to view more information. The map control in the upper right corner can be used to toggle map layers on and off. The red outline is the border of New Castle County and can be turned on and off. Each type of postal code can also be turned on and off.