The ZIP code is the system of postal codes used by the United States Postal Service (USPS) to define locations when distributing mail. The letters ZIP is an acronym for Zone Improvement Plan, and this system was created so that the mail travels more efficiently, and therefore more quickly. The basic format consists of five numerical digits: a three-digit prefix indicating regional location, followed by two other numerals indicating a more local area. An extended ZIP + 4 code includes the five digits of the ZIP code, a hyphen, and four more digits that determine a more precise location within the ZIP code. The term ZIP Code was originally registered as a servicemark (a type of trademark) by the U.S. Postal Service but its registration has since expired.
Michigan ZIP codesEdit
All Michigan ZIP codes begin with either 48- or 49-. The three digit prefixes are each assigned to a sectional center facility (SCF), the processing and distribution center for the USPS. There are eleven SCFs in Michigan.
|SCF cite||Prefixes serviced|
|Royal Oak||480, 483|
Additionally, ZIP code boundaries do not always follow geopolitical boundaries. A ZIP code may include portions of another community. For example, 48306 is assigned to Rochester, but only includes a small portion of the community. It serves much larger areas of Rochester Hills, Oakland Charter Township and Goodison. As a result, the USPS permits these communities to be used as alternative places when mailing items.