The main window of Zip Express provides a search by zip code, city, county, state or area code, displaying as you type the potential matches. 

The Preferences window gives the possibility to modify the default settings of the program. 

The Appearance option allows you to set the criteria that will be used for searching, the informations displayed in the Zip Code List Box and the Case Sensitivity. 

The Modify Format window permits the user to change the formats in which the informations are displayed according his own preferences.