ZIP Code 48421 — Columbiaville, MI
48421 is a standard (street delivery) ZIP code serving Columbiaville, Michigan, in Lapeer 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 48421 at a glance
| ZIP code | 48421 |
|---|---|
| Primary city | Columbiaville |
| State | Michigan (MI) |
| County | Lapeer FIPS 26087 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Detroit |
| Population | 6,935 |
| Coordinates | 43.153210, -83.392620 |
How ZIP+4 works in 48421
The four digits after the hyphen encode a delivery segment inside 48421. 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 48421 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 48421.
| ZIP | City | Distance |
|---|---|---|
| 48464 | Otter Lake, MI | 4.5 mi |
| 48463 | Otisville, MI | 6.6 mi |
| 48435 | Fostoria, MI | 6.8 mi |
| 48446 | Lapeer, MI | 7.5 mi |
| 48423 | Davison, MI | 9.9 mi |
| 48461 | North Branch, MI | 10 mi |
| 48746 | Millington, MI | 10.7 mi |
| 48437 | Genesee, MI | 11.7 mi |
| 48412 | Attica, MI | 12.8 mi |
| 48506 | Flint, MI | 13 mi |
| 48760 | Silverwood, MI | 13.5 mi |
| 48744 | Mayville, MI | 13.5 mi |
Questions about 48421
What is the ZIP+4 code for 48421?
48421 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 48421, you need to look up a specific street address to get them.
What city is 48421?
48421 is assigned to Columbiaville, Michigan, in Lapeer 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.