Boulder County ZIP Codes
Boulder County is a county of Colorado.
- ZIP codes
- 27
- Cities & towns
- 14
- Area codes
- 3
- Land area
- 726 sq mi
Every ZIP code in Boulder County
| ZIP code | City |
|---|---|
| 80020 | Broomfield |
| 80025 | Eldorado Springs |
| 80026 | Lafayette |
| 80027 | Louisville |
| 80038 | Broomfield |
| 80301 | Boulder |
| 80302 | Boulder |
| 80303 | Boulder |
| 80304 | Boulder |
| 80305 | Boulder |
| 80306 | Boulder |
| 80307 | Boulder |
| 80308 | Boulder |
| 80309 | Boulder |
| 80310 | Boulder |
| 80314 | Boulder |
| 80455 | Jamestown |
| 80466 | Nederland |
| 80471 | Pinecliffe |
| 80481 | Ward |
| 80501 | Longmont |
| 80502 | Longmont |
| 80503 | Longmont |
| 80510 | Allenspark |
| 80533 | Hygiene |
| 80540 | Lyons |
| 80544 | Niwot |
We do not publish a delivery type (standard, PO box, unique) or a neighbourhood for each ZIP. USPS delivery-type products are licensed, and no clean-rights source maps ZIP codes to neighbourhoods — so the Boulder County codes above are listed without a column we would have to invent.
Cities and towns in Boulder County
A further 5 places in Boulder County appear in the postal source without a page of its own; their codes are in the table above and each one links to its own page.
Area codes covering Boulder County
Telephone and postal boundaries are drawn by different bodies, so these codes overlap the county without matching its edges.
Where Boulder County's ZIP codes sit
- Reference points and footprint
- Not an official NANPA boundary
- Not a USPS delivery area
Scope every ZIP code recorded in Boulder County. Source GeoNames US postal codes (2026-07 postal dump), Census 2024 county Gazetteer (2024 Gazetteer) and geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot). Updated . The outline is a convex envelope of ZIP reference points, not a jurisdiction boundary.