Pronunciation: [zˈɪp plˈʌs fˈɔː] (IPA) 
"Zip plus four" is a standardized postal code system used in the United States for efficient mail delivery. The word "zip" is spelled /zɪp/ with a short "i" sound as in "sit". The word "plus" is spelled /plʌs/ with a short "u" sound as in "bus". The number "four" is spelled /fɔːr/ with an "o" sound as in "more". When combined, the word is pronounced /zɪp plʌs fɔːr/, with emphasis on the "zip" syllable.
Zip plus four is a term that refers to a detailed postal code system used in the United States. It is a further extension of the five-digit zip code, designed to enhance the accuracy and efficiency of mail delivery. The term "zip" stands for "Zone Improvement Plan," and the plus four denotes the additional four-digit extension added to a standard zip code.
The zip plus four code provides a greater level of specificity by narrowing down the geographical area to a particular neighborhood, building, or even a specific company. The additional four digits serve to identify a more precise location within the given zip code area. This information aids postal workers in swiftly and accurately delivering mail to the intended recipient.
The plus four extension plays a crucial role in expediting mail processing and routing. It enables the United States Postal Service (USPS) to sort mail more efficiently, improving overall delivery time and reducing potential errors. Additionally, it allows for better organization of mail distribution within large companies, apartment complexes, and other densely populated areas.
Zip plus four codes are most commonly used for business mailings, and they are often supplied by the USPS database or obtained through an address verification service. It is important for individuals and organizations to consistently include the plus four code in their addresses to ensure mail reaches the correct destination in a timely manner, especially when dealing with high-volume mailings or commercial correspondence.
