ZIP Code 48178 — South Lyon, MI
48178 is a standard (street delivery) ZIP code serving South Lyon, Michigan, in Oakland 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 48178 at a glance
| ZIP code | 48178 |
|---|---|
| Primary city | South Lyon |
| State | Michigan (MI) |
| County | Oakland FIPS 26125 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 37,789 |
| Coordinates | 42.444630, -83.663990 |
How ZIP+4 works in 48178
The four digits after the hyphen encode a delivery segment inside 48178. 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 48178 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 48178.
| ZIP | City | Distance |
|---|---|---|
| 48165 | New Hudson, MI | 4.5 mi |
| 48189 | Whitmore Lake, MI | 6.5 mi |
| 48168 | Northville, MI | 6.8 mi |
| 48167 | Northville, MI | 6.8 mi |
| 48116 | Brighton, MI | 7.2 mi |
| 48374 | Novi, MI | 7.4 mi |
| 48139 | Hamburg, MI | 7.4 mi |
| 48393 | Wixom, MI | 8 mi |
| 48105 | Ann Arbor, MI | 8.1 mi |
| 48170 | Plymouth, MI | 8.5 mi |
| 48381 | Milford, MI | 8.9 mi |
| 48380 | Milford, MI | 9.3 mi |
Questions about 48178
What is the ZIP+4 code for 48178?
48178 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 48178, you need to look up a specific street address to get them.
What city is 48178?
48178 is assigned to South Lyon, Michigan, in Oakland 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.