ZIP codes in Hancock County
21 ZIPs touch Hancock County, Illinois. The blue dashed line is the county border; orange ZIPs reach into it.
21
ZIP codes
12
cross the county line
24,069
people in these ZIPs
102
counties in IL
Most people
Hancock County ZIP list
More counties in Illinois
- Franklin County20
- Fulton County24
- Gallatin County9
- Greene County14
- Grundy County16
- Hamilton County13
- Hardin County6
- Henderson County17
- Henry County24
- Iroquois County28
- Jackson County23
- Jasper County15
Questions people actually ask
How many ZIP codes are in Hancock County, Illinois?
21 ZIP codes reach into Hancock County, including 1 PO Box or single-address ZIPs placed by the town they serve. 12 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Hancock County has the most people?
62321 (Carthage) has about 3,576 residents, the most of any ZIP touching Hancock County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Hancock County and another county?
Yes. ZIP codes follow mail routes, not county lines. Rows marked with a percentage show how much of that ZIP’s land is in Hancock County. For one address, pin the exact spot on the ZIP finder to see its county.
Where does this list come from?
ZIP areas and their county overlaps come from the Census Bureau’s 2020 ZIP Code Tabulation Area to county relationship file. PO Box ZIPs have no area, so each is placed in the county of the ZIP area nearest the town it serves.
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Updated 2026-11-10 · Where the data comes from