Why ZIP codes have 5 numbers — and what they each mean
Wednesday marks the 52nd birthday of the introduction of ZIP codes in the US.
Though the explosion of business mail is mostly responsible for the Zoning Improvement Plan (ZIP), the idea started during World War II, when the first two numbers were introduced.
The initial zoning address system took effect in 1943 when thousands of postal employees left to serve the military during World War II, leaving the system understaffed and in need of simplification. To start, 124 of the largest US cities were classified with two numbers — the first identifying the city and the second the state. The numbers were intended to make sorting easier for less experienced employees.
The postal system implemented the three other numbers 20 years later in 1963, as mail volume grew.
What each number means
- The first digit designates a broad area, which ranges from zero for the Northeast to nine for the far West.
- The two following digits are the code of a central post office facility in that region.
- The last two digits designate small post offices or postal zones.
Today, the zip codes are an inevitable part of the postal address. Without zipping codes, the correspondence and online orders would take much longer to be delivered. With the zip codes, the system is much simplified. But new zip codes are being added constantly. So you need to recheck the codes in case you do not remember it well https://areaphonecodes.com/united-states/954 . There are many online resources for it.