ZIP Codes in Boulder, CO
Boulder uses 6 ZIP codes, all in Boulder County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 6 Boulder ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 80301 | standard | Boulder | 25,007 |
| 80302 | standard | Boulder | 29,569 |
| 80303 | standard | Boulder | 24,996 |
| 80304 | standard | Boulder | 25,383 |
| 80305 | standard | Boulder | 16,291 |
| 80310 | standard | Boulder | 7,692 |
Finding a ZIP+4 in Boulder
Knowing which of these 6 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same Boulder street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of Boulder addresses and download it complete.