

Then they are left two spaces before the ZIP code is written, such as For a correct notation: top of the line of the Postal Code is the city, followed by the state. The addition of the fourth digit met many difficulty so since today there is no more longer necessary. Between the fifth and sixth digit it is always a hyphen. The two numbers that follow represent the sector and the last two digits are for the segment. The first three digits describe the routing zone (routing) or the center of processing and distribution and the next two numbers define the post office. The American ZIP code consists of nine digits. Thus, for example, Agawam, Massachusetts has the lowest numerical code: 99950, while in that Alaska postal code increases by 4 digits. The postal codes begin on the east coast and reaches the West, increasing more and more digits. In the US, there are about 30,000 post offices, each of which has its own code. In North America, the name of the place acts as the ZIP code. The improvement plan is managed by the postal service of the United States, United States Postal Service.

In the USA the zip code indicates the Zones. At the time there was a five-digit code, which has been narrowed to four digits in 1983.

The modern postal code system was introduced on 1 July 1963. In 1840 were introduced the stamps and later, in 1961, there were established the first postal organizations. Even at that time it was used a stamp of one or two digits, tones that practically were the forerunners of today's postal codes. Already in 1672, under the British colonial administration, there was a regular postal service between New York and Boston. The first evidence of the delivery of a paid letter, dates back to 1639, when Richard Fairbanks has sent a letter to Massachusetts on behalf of the government agency in Boston.
