Final answer:
The ZIP+4 code was introduced in 1983 to improve mail delivery efficiency by adding four additional digits to the existing five-digit ZIP code. These extra digits identify a more specific location, like a city block or an office building.
Step-by-step explanation:
Introduction of ZIP+4 Code
The ZIP+4 code was introduced by the United States Postal Service (USPS) in 1983. The ZIP+4 code is an extension of the original five-digit ZIP code. The purpose of introducing the ZIP+4 code was to improve the efficiency and accuracy of mail delivery. It is made up of the original five-digit code, followed by a hyphen, and four additional digits. These four additional digits represent a specific geographic segment, such as a city block, office building, or other unit that could aid in mail sorting and delivery.
Significance of the ZIP+4 Code
Adding the +4 digits to the standard ZIP code allows for a more precise location to be identified, facilitating faster sorting and delivery of mail. It is particularly useful for locations receiving a large volume of mail and where rapid processing is essential. For instance, a single large business or apartment building might have its own unique ZIP+4 code. While the use of the ZIP+4 code is encouraged for the benefits it provides, it is not mandatory for mail senders, and mail without the +4 code will still be delivered.