Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — PREFIX/803

ZIP codes starting with 803

ZIP codes
11
States
CO
Largest city
Boulder, CO
Population
128,938

The first three digits of a ZIP code identify a sectional center facility — the postal processing plant that sorts mail for the area. It is a mail-routing grouping, not an administrative boundary.

Every ZIP code in 803xx

ZIP codes starting with 803
ZIP City Type Population Median income Median home
80301 Boulder , CO Standard 25,007 $95,207 $793,200
80302 Boulder , CO Standard 29,569 $61,698 $1,190,800
80303 Boulder , CO Standard 24,996 $78,555 $961,900
80304 Boulder , CO Standard 25,383 $126,558 $1,210,200
80305 Boulder , CO Standard 16,291 $126,107 $1,032,900
80306 Boulder , CO No street area — — —
80307 Boulder , CO No street area — — —
80308 Boulder , CO No street area — — —
80309 Boulder , CO No street area — — —
80310 Boulder , CO Standard 7,692 — —
80314 Boulder , CO No street area — — —

Cite this page

zipcodes.pro. “ZIP codes starting with 803.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/prefix/803

Underlying data is public domain or openly licensed — sources, vintages and licences.