Colorado ZIP Prefix Families and Postal Areas
Colorado's postal map can be grouped by prefix family, but it cannot be reduced here to a complete list of five-digit codes. Each listed group uses “xx” to mark the unlisted final digits. Hundreds of active ZIPs, PO-box-only ZIPs, and unique institutional ZIPs exist statewide, but the complete current USPS export is not available. The Post Office column therefore describes broad postal associations, not verified individual post offices or a code-to-office match.
| ZIP | Areas Covered | Post Office | Notes |
|---|---|---|---|
| 800xx prefix family | Denver metro north and east, including Denver, Aurora, Arvada, Westminster, and Broomfield-area postal names | Denver-area associations vary | Postal and municipal boundaries diverge; verify an exact street. |
| 801xx prefix family | South metro, including Englewood, Littleton, Centennial, Parker, Castle Rock, and nearby areas | South-metro postal names vary | Check the parcel county before choosing an assessor. |
| 802xx prefix family | Denver postal stations and Denver-area delivery | Denver station names vary | A Denver postal label does not prove a Denver County parcel. |
| 803xx prefix family | Boulder, Gunbarrel, and nearby Boulder County postal areas | Boulder-area associations vary | City, county, and postal lines can differ at the edge. |
| 804xx prefix family | Mountain and foothill places, northwest metro, Golden, Evergreen, Idaho Springs, and assigned Steamboat ranges | Mountain and foothill names vary | Large rural delivery areas may serve more than one community. |
| 805xx prefix family | Fort Collins, Loveland, Longmont, and the northern Front Range | Northern Front Range names vary | Larimer, Weld, and Boulder county lines do not set ZIP borders. |
| 806xx prefix family | North and east metro and Weld-area postal names | North and east area names vary | Rural routes and unincorporated places may use a postal city name. |
| 807xx prefix family | Northeast Colorado and eastern plains communities | Eastern plains names vary | Rural delivery and PO boxes make exact address checks useful. |
| 808xx prefix family | Colorado Springs and northeast El Paso areas, plus eastern plains postal regions | Colorado Springs sectional center association | The postal region is not one city limit. |
| 809xx prefix family | Colorado Springs and Pikes Peak postal areas | Pikes Peak associations vary | A postal label may cross a city or county line. |
| 810xx prefix family | Pueblo and southeast or south-central communities | Pueblo and regional names vary | Verify county before searching deeds or court records. |
| 811xx prefix family | San Luis Valley communities | San Luis Valley names vary | County assessor and GIS records are stronger parcel keys. |
| 812xx prefix family | Upper Arkansas and central-south communities | Regional names vary | Post-office geography does not follow incorporated limits. |
| 813xx prefix family | Durango, southwest Colorado, and Four Corners communities | Southwest names vary | Verify city/state-to-ZIP through USPS and use the county parcel map. |
| 814xx prefix family | Grand Junction and western Colorado postal areas | Western Colorado names vary | Mesa, Delta, and Montrose county lines differ from postal names. |
| 815xx prefix family | Grand Junction and the Grand Valley | Grand Valley names vary | Confirm the exact address and keep the assessor situs city separate. |
| 816xx prefix family | Roaring Fork and northwest mountain communities | Mountain-area names vary | Rural routes, PO boxes, and multiple place names are common. |
These rows group regions, not specific codes. They do not show every community association, post office, PO-box-only code, or institutional code. A Colorado ZIP code directory can orient a regional search, but USPS confirms the current exact code. Its City State Product and AIS files are updated monthly, so an exact list needs a current official file rather than a copied static directory. Verify the mailing address and postal city with USPS.
Find a Colorado ZIP Code and Parcel
To research an address within one postal area, first confirm the ZIP for the exact street address. Then decide whether the question concerns the land at that location or the owner's mailing address. Colorado's state parcel service has distinct ZIP fields for each. No statewide resident browse by ZIP or standard county assessor form is documented.
- Use USPS By Address with the full street address and city and state to confirm the standardized ZIP and postal city.
- Query the state parcel layer by situs ZIP when the goal is land physically in that postal area. Keep owner-mailing ZIP results separate.
- Use the map to confirm the county and parcel, then open that county assessor's record for property detail.
- For voter information, use Go Vote Colorado for an individual record or contact the county or state custodian about a lawful, redacted public-file request. It is not a ZIP-wide browse.
When the address is known, a ZIP helps route the search but does not name every person at that location. Once the USPS check and parcel county agree, the Colorado street directory process covers the next step: address, assessor parcel, and recorder record.
Colorado USPS ZIP Lookup Modes
The USPS ZIP Lookup answers three different questions. By Address verifies the postal form for one location. City and State returns the ZIPs associated with that postal city. A ZIP-to-city search returns the city names served by a code. Choose the mode that fits the question; a list of names returned for one town is not a list of every town inside a municipal border.
The USPS ZIP basics page explains that postal areas do not always follow city limits and that a returned postal code does not prove a person or company is at an address. For a post office or station, use the USPS locator and check its local results. Neither source supplies a complete person directory.
Colorado Parcel Records Hold Two ZIP Fields
The Colorado public parcel service is the documented statewide property source with separate postal fields. A query by situs ZIP can return parcels located in a delivery area; a query by owner-mailing ZIP can return owners whose tax mail goes there. Those are different searches and can point to different places.
Check these fields in the Colorado public parcel layer, then use its county and parcel values to reach the local assessor. Not every county form exposes both postal fields, so do not assume a county search box accepts a ZIP filter.
| Documented field | What it refers to | How to read it |
|---|---|---|
sitAddZip | ZIP attached to the situs address | Use for the parcel's physical location; confirm with the county map. |
ownAddZip | ZIP attached to the owner's mailing address | Tax mail may go to another city or region. |
countyName and countyFips | County name and code | Route deeds and assessments to that county custodian. |
situsAdd, sitAddCty | Site street address and city | Compare with the USPS standard form and local parcel record. |
The service is a county-fed map and data layer, not a certified assessment or title record. Confirm ownership, value, and legal description at the county level.
Colorado ZIPs Can Cross County Lines
A mailing city name is not a reliable way to choose the county office. One postal city can appear on parcels in more than one county, and one broad delivery area can serve incorporated and unincorporated places. Colorado's statewide map and county parcel layers help show which local custodian holds an assessment or deed.
For example, a Denver-area delivery label does not prove the parcel sits in the City and County of Denver. The parcel map's county value should control the assessor and recorder route. A court case belongs to the filing court, a voter record to its election custodian, and a postal code to USPS delivery geography. These boundaries answer separate questions.
Colorado ZIP Directory Groups Regional Areas
The 800xx through 816xx families in the table show regional patterns rather than local borders. The north and east metro, Denver, the southern Front Range, the mountain counties, eastern plains, San Luis Valley, southwest, and Western Slope each have different post-office names and county systems.
A broad family such as 804xx or 816xx can cover rural delivery areas and more than one community. A postal city in the prefix group is not necessarily an incorporated town, and the family does not reveal how many active five-digit codes exist. That is why this directory uses regional associations only and points to USPS for the exact location.
Colorado PO-Box and Unique ZIPs
Colorado has PO-box-only and unique institutional ZIPs, but the research did not identify their exact current codes or associated offices. Do not infer an institution, post office, or neighborhood from a prefix family. Use USPS city/state search for a town, ZIP-to-city for places served, and the postal locator for a station or service point.
Rural routes and PO boxes are common in the eastern plains and mountain regions. For a house, farm, or business parcel, compare the exact street address against USPS and the county parcel map. A mailing address can name a postal place that differs from the local jurisdiction; the assessor's county still governs property records.
Denver ZIP Lines and the Old Street Grid
Postal geography and street geography change on different tracks. Denver's numbered grid was standardized in 1887, and ordinances in 1897 and 1904 changed street names and numbering. The Denver Public Library street-name guide helps explain why a historic street label can differ from a modern map, but it does not define current ZIP boundaries.
Use the Colorado State Map Viewer and local parcel map for current city, county, and parcel lines. Use USPS to verify the current delivery form. When an older Denver address is involved, the street's legal description or lot and block can bridge the historical and modern address. The official sources available here do not document a ZIP realignment year or neighborhood-level postal boundary history.
Colorado ZIP Search Does Not List Residents
A ZIP can narrow parcel data, but it does not name everyone who receives mail at an address. Colorado's state voter service is an individual self-service tool; the research did not find a public ZIP-wide browse for voters. A lawful public voter-file request goes to the state or county custodian and may require identification or redaction of confidential fields.
For property context, use situs ZIP and owner mailing ZIP as separate filters in the state layer, then confirm the parcel with its county. For one person, use an official individual channel and describe only what that record shows. Do not convert regional postal families into a count of residents or households.
Colorado ZIP Code Lines and City Limits
ZIP boundaries follow delivery needs, not Colorado's city, county, or district lines. A mailing city may cover an unincorporated pocket or a neighboring municipality, and one city can use more than one postal association. County GIS and the State Map Viewer show land and jurisdiction; USPS confirms delivery. Check both before sending a deed search to a county or treating a postal name as proof of residence.
A ZIP-based result only confirms the postal association returned by the official lookup. It does not prove that a particular person or business occupies the street address. Colorado's parcel service adds useful situs and mailing fields, but its county-fed data must still be checked with the local assessor.
- ZIP and ZIP+4
- The five-digit delivery area and an added four digits that narrow a delivery segment; the added digits do not set a city or county boundary.
- PO-box-only ZIP
- A postal code used for post-office box delivery rather than a general street-delivery area.
- Unique ZIP
- A postal code assigned to a single institution or other high-volume recipient, rather than a general neighborhood.
- Carrier route
- A delivery route within a postal area, finer than the ZIP and not a separate city or county.