ZIP codes in Franklin County
7 ZIPs touch Franklin County, Washington. The blue dashed line is the county border; orange ZIPs reach into it.
7
ZIP codes
3
cross the county line
117,962
people in these ZIPs
39
counties in WA
Most people
Franklin County ZIP list
More counties in Washington
- Clallam County11
- Clark County24
- Columbia County5
- Cowlitz County12
- Douglas County13
- Ferry County10
- Garfield County2
- Grant County19
- Grays Harbor County22
- Island County8
- Jefferson County9
- King County123
Questions people actually ask
How many ZIP codes are in Franklin County, Washington?
7 ZIP codes reach into Franklin County. 3 of them are only partly in the county and also cover a neighboring county.
Which ZIP code in Franklin County has the most people?
99301 (Pasco) has about 87,044 residents, the most of any ZIP touching Franklin County, in the Census Bureau’s ACS 2020–2024 estimates.
Can a ZIP code be in Franklin 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 Franklin 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