What is Zip Code?

The term ZIP is an acronym for Zone Improvement Plan. It was chosen to suggest that the mail travels more efficiently and quickly (zipping along) when senders use the code in the postal address the basic format consists of five digits. There are no ZIP codes reserved for designating mail bound for foreign destinations (with the exception of U.S. military units stationed outside of the United States), and therefore, international outbound mail should not include a ZIP code in the delivery address.

In order to promote the idea of ZIP codes, Mr. Zip” appeared as the cartoon mascot for the campaign, touting Put ZIP in your mail!” While Mr. Zip is obviously a fictional figure, a Philadelphia postal inspector named Robert Moon is widely considered to be the real-life version and the father of the ZIP code even though the Postal Service refused to give him sole credit for the invention.

Like area codes , ZIP codes are sometimes divided and changed, especially when a rural area becomes suburban Typically, the new codes become effective once announced, and a grace period (e.g., one year) is provided in which the new and old codes are used concurrently so that postal patrons in the affected area can notify correspondents, order new stationery, etc.

Reference : USPS

Top Zip Code by Population in United States

Zip CodeCityStateAreaCodePopulationTimezone
Zip Code 77449KatyTexas832 / 346 / 281124,161Central (GMT -06:00)
Zip Code 77494KatyTexas281 / 346 / 832121,708Central (GMT -06:00)
Zip Code 79936El PasoTexas915118,608Mountain (GMT -07:00)
Zip Code 77084HoustonTexas281 / 832 / 346109,885Central (GMT -06:00)
Zip Code 90011Los AngelesCalifornia323109,773Pacific (GMT -08:00)
Zip Code 60629ChicagoIllinois773 / 872 / 312 / 708108,911Central (GMT -06:00)
Zip Code 90650NorwalkCalifornia562104,861Pacific (GMT -08:00)
Zip Code 08701LakewoodNew Jersey732 / 848104,346Eastern (GMT -05:00)
Zip Code 78521BrownsvilleTexas956103,832Central (GMT -06:00)
Zip Code 78572MissionTexas956103,451Central (GMT -06:00)
Zip Code 90201Bell GardensCalifornia323102,119Pacific (GMT -08:00)
Zip Code 92335FontanaCalifornia909102,029Pacific (GMT -08:00)
Zip Code 92336FontanaCalifornia909101,643Pacific (GMT -08:00)
Zip Code 78660PflugervilleTexas512101,532Central (GMT -06:00)
Zip Code 90250HawthorneCalifornia310 / 424100,092Pacific (GMT -08:00)
Zip Code 94565PittsburgCalifornia92598,901Pacific (GMT -08:00)
Zip Code 77433CypressTexas832 / 281 / 34698,872Central (GMT -06:00)
Zip Code 11226BrooklynNew York71897,341Eastern (GMT -05:00)
Zip Code 90280South GateCalifornia32397,204Pacific (GMT -08:00)
Zip Code 90805Long BeachCalifornia562 / 31096,340Pacific (GMT -08:00)