ZIP Code 80027 — Louisville, CO
80027 is a standard (street delivery) ZIP code serving Louisville, Colorado, in Boulder County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 80027 at a glance
| ZIP code | 80027 |
|---|---|
| Primary city | Louisville |
| State | Colorado (CO) |
| County | Boulder FIPS 08013 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 34,127 |
| Coordinates | 39.950800, -105.163540 |
How ZIP+4 works in 80027
The four digits after the hyphen encode a delivery segment inside 80027. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 80027 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 80027.
| ZIP | City | Distance |
|---|---|---|
| 80303 | Boulder, CO | 3 mi |
| 80305 | Boulder, CO | 4.9 mi |
| 80021 | Broomfield, CO | 4.9 mi |
| 80020 | Broomfield, CO | 4.9 mi |
| 80026 | Lafayette, CO | 5.4 mi |
| 80007 | Arvada, CO | 6.1 mi |
| 80310 | Boulder, CO | 6.4 mi |
| 80301 | Boulder, CO | 7 mi |
| 80025 | Eldorado Springs, CO | 7 mi |
| 80005 | Arvada, CO | 7.1 mi |
| 80023 | Broomfield, CO | 8.3 mi |
| 80031 | Westminster, CO | 8.3 mi |
Questions about 80027
What is the ZIP+4 code for 80027?
80027 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 80027, you need to look up a specific street address to get them.
What city is 80027?
80027 is assigned to Louisville, Colorado, in Boulder County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.