ZIP Code 91740 — Glendora, CA
91740 is a standard (street delivery) ZIP code serving Glendora, California, in Los Angeles 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 91740 at a glance
| ZIP code | 91740 |
|---|---|
| Primary city | Glendora |
| State | California (CA) |
| County | Los Angeles FIPS 06037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 26,168 |
| Coordinates | 34.118840, -117.853400 |
How ZIP+4 works in 91740
The four digits after the hyphen encode a delivery segment inside 91740. 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 91740 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.
Other ZIP codes in Glendora
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 91740.
| ZIP | City | Distance |
|---|---|---|
| 91724 | Covina, CA | 2.6 mi |
| 91773 | San Dimas, CA | 2.6 mi |
| 91723 | Covina, CA | 3 mi |
| 91722 | Covina, CA | 3.4 mi |
| 91741 | Glendora, CA | 3.4 mi |
| 91791 | West Covina, CA | 4.6 mi |
| 91768 | Pomona, CA | 5.3 mi |
| 91750 | La Verne, CA | 5.4 mi |
| 91790 | West Covina, CA | 6 mi |
| 91010 | Duarte, CA | 6.2 mi |
| 91706 | Baldwin Park, CA | 6.8 mi |
| 91789 | Walnut, CA | 6.9 mi |
Questions about 91740
What is the ZIP+4 code for 91740?
91740 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 91740, you need to look up a specific street address to get them.
What city is 91740?
91740 is assigned to Glendora, California, in Los Angeles 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.