ZIP Code 85378 — Surprise, AZ
85378 is a standard (street delivery) ZIP code serving Surprise, Arizona, in Maricopa 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 85378 at a glance
| ZIP code | 85378 |
|---|---|
| Primary city | Surprise |
| State | Arizona (AZ) |
| County | Maricopa FIPS 04013 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Phoenix |
| Population | 9,765 |
| Coordinates | 33.641620, -112.320120 |
How ZIP+4 works in 85378
The four digits after the hyphen encode a delivery segment inside 85378. 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 85378 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 Surprise
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 85378.
| ZIP | City | Distance |
|---|---|---|
| 85373 | Sun City, AZ | 2.4 mi |
| 85375 | Sun City West, AZ | 2.9 mi |
| 85351 | Sun City, AZ | 3.3 mi |
| 85335 | El Mirage, AZ | 3.8 mi |
| 85363 | Youngtown, AZ | 4 mi |
| 85379 | Surprise, AZ | 4.1 mi |
| 85374 | Surprise, AZ | 4.3 mi |
| 85382 | Peoria, AZ | 4.3 mi |
| 85381 | Peoria, AZ | 5.5 mi |
| 85345 | Peoria, AZ | 6.3 mi |
| 85388 | Surprise, AZ | 7 mi |
| 85307 | Glendale, AZ | 7.5 mi |
Questions about 85378
What is the ZIP+4 code for 85378?
85378 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 85378, you need to look up a specific street address to get them.
What city is 85378?
85378 is assigned to Surprise, Arizona, in Maricopa 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.