ZIP Code 61728 — Colfax, IL
61728 is a standard (street delivery) ZIP code serving Colfax, Illinois, in McLean 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 61728 at a glance
| ZIP code | 61728 |
|---|---|
| Primary city | Colfax |
| State | Illinois (IL) |
| County | McLean FIPS 17113 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,359 |
| Coordinates | 40.575460, -88.625390 |
How ZIP+4 works in 61728
The four digits after the hyphen encode a delivery segment inside 61728. 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 61728 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 61728.
| ZIP | City | Distance |
|---|---|---|
| 61730 | Cooksville, IL | 6.4 mi |
| 61720 | Anchor, IL | 6.5 mi |
| 61731 | Cropsey, IL | 7.8 mi |
| 61753 | Lexington, IL | 9.5 mi |
| 61737 | Ellsworth, IL | 10 mi |
| 61722 | Arrowsmith, IL | 10.7 mi |
| 61770 | Saybrook, IL | 10.8 mi |
| 61726 | Chenoa, IL | 12 mi |
| 61739 | Fairbury, IL | 12.2 mi |
| 61776 | Towanda, IL | 12.7 mi |
| 61773 | Sibley, IL | 13.1 mi |
| 61775 | Strawn, IL | 14.3 mi |
Questions about 61728
What is the ZIP+4 code for 61728?
61728 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 61728, you need to look up a specific street address to get them.
What city is 61728?
61728 is assigned to Colfax, Illinois, in McLean 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.