Colorado ZIP codes
Colorado holds 645 ZIP codes between 80001 and 81658. The tables rank the places and counties with the most codes; the guide below decodes the numbering.
Places with the most ZIP codes in Colorado
| Place | ZIP codes |
|---|---|
| Denver | 66 |
| Colorado Springs | 53 |
| Aurora | 17 |
| Littleton | 16 |
| Pueblo | 12 |
| Boulder | 11 |
| Fort Collins | 9 |
| Englewood | 7 |
| Arvada | 7 |
| Grand Junction | 7 |
| Greeley | 6 |
| Westminster | 4 |
| Broomfield | 4 |
| Longmont | 4 |
| Golden | 4 |
| Brighton | 3 |
| Castle Rock | 3 |
| Durango | 3 |
| Loveland | 3 |
| Montrose | 3 |
Colorado counties by ZIP count
| County | ZIP codes |
|---|---|
| El Paso | 66 |
| Denver | 55 |
| Weld | 39 |
| Jefferson | 33 |
| Arapahoe | 28 |
| Boulder | 27 |
| Adams | 26 |
| Larimer | 24 |
| Mesa | 19 |
| Pueblo | 17 |
Reading a Colorado ZIP code
Colorado holds 645 ZIP codes between 80001 and 81658, spread over 64 counties. Denver leads the state with 66 codes, ahead of Colorado Springs with 53. Every code here opens with the digit 8: that opening number is the national postal region Colorado belongs to, the next two digits name the sectional center that sorts the mail, and the final two point to the local office. A ZIP+4 suffix narrows delivery to a block face. Boundaries follow carrier routes rather than city limits, which is why Denver spreads across 66 codes while some rural codes cross county lines.
Source: GeoNames postal dataset (CC BY 4.0), snapshot of 2026-07-09. Counts cover standard delivery ZIPs listed for Colorado; unique and PO box codes may add to these totals.
Last updated: · Methodology and sources