Find complete information about all ZIP codes in Alto-pass, Illinois. Our interactive map shows the postal code boundaries and locations throughout the city.
Alto-pass Postal Codes
The postal system in Alto-pass is organized to efficiently serve both residential and commercial areas. Each ZIP code represents a specific delivery zone within the city limits.
ZIP Code (Zip Code) - Representación de área del código postal de los correos de los Estados Unidos.
Código Postal EEUU - ILLINOIS - ALTO-PASS
PRIMARY: Refers to the main name of the city, typically its official designation. Although the city might have an ACCEPTABLE alternative name, the primary name remains the official one.
ACCEPTABLE: Indicates a suitable alternative city name. Commonly abbreviated city names are often listed as unacceptable because abbreviations are not considered an acceptable city name format.
IMPROPER/NOT ACCEPTABLE: Denotes that an inappropriate city name was entered or received based on the provided information.
UNIQUE: Assigned to a business, government agency, or entity with a significant mail volume. This designation depends on the average daily volume of letter-sized mail received, the availability of ZIP code numbers in the postal area, and a cost-benefit analysis by the postal service.
