Why does the zips database only include one city per zip?
Our US Zip Code Database only includes a single city for each zip code under the city field. This is primary "city" as listed by the United State Postal Service. This is typically a city, but it could be a neighborhood. If you want to get a mapping of all cities that overlap the zip code, you'll need our US Cities Database. It lists all zip codes that overlap a city in the zips field. You can query the zips field to get all cities that overlap.