First three digits · Kentucky
ZIP Codes Starting with
45 ZIP codes start with 423, sorted at the Evansville, IN (SCF 476) sectional center (USPS labeling list L005, effective October 1, 2026) in Kentucky: 40 residential ZIP codes across 5 counties and 5 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 423 mean?
The first digit, 4, is one of ten national areas (Indiana, Kentucky, Michigan and Ohio). The first three, 423, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 423 to the Evansville, IN (SCF 476) facility. The last two digits pick the delivery area. By residents, the largest town names among the 423 ZIP codes are Owensboro, Greenville, Central City, Beaver Dam, Utica and Philpot.
The same facility sorts 6 prefixes, 248 ZIP codes in all: 420, 423, 424, 475, 476, 477.
Where are the 423 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 423
| County | ||||||
|---|---|---|---|---|---|---|
| 42301 | Owensboro | Daviess County | 45,445 | 263 | $67k | $198k |
| 42302 | Owensboro | Daviess County | PO Box or unique | – | – | – |
| 42303 | Owensboro | Daviess County | 42,119 | 863 | $65k | $198k |
| 42304 | Owensboro | Daviess County | PO Box or unique | – | – | – |
| 42320 | Beaver Dam | Ohio County | 9,128 | 61 | $55k | $150k |
| 42321 | Beech Creek | Muhlenberg County | 553 | 151 | $54k | $80k |
| 42322 | Beech Grove | McLean County | 53 | 92 | – | – |
| 42323 | Beechmont | Muhlenberg County | 852 | 578 | $53k | $162k |
| 42324 | Belton | Muhlenberg County | 1,228 | 39 | $78k | $158k |
| 42325 | Bremen | Muhlenberg County | 2,045 | 70 | $79k | $134k |
| 42326 | Browder | Muhlenberg County | 283 | 18 | $42k | $163k |
| 42327 | Calhoun | McLean County | 4,206 | 34 | $67k | $168k |
| 42328 | Centertown | Ohio County | 1,158 | 18 | $58k | $97k |
| 42330 | Central City | Muhlenberg County | 9,367 | 90 | $50k | $151k |
| 42332 | Cleaton | Muhlenberg County | 20 | 38 | – | – |
| 42333 | Cromwell | Ohio County | 644 | 18 | $34k | $85k |
| 42334 | Curdsville | Daviess County | PO Box or unique | – | – | – |
| 42337 | Drakesboro | Muhlenberg County | 1,683 | 45 | $37k | $76k |
| 42338 | Dundee | Ohio County | 12 | 4 | – | – |
| 42339 | Dunmor | Muhlenberg County | 840 | 23 | $47k | $111k |
| 42343 | Fordsville | Ohio County | 1,267 | 16 | $53k | $87k |
| 42344 | Graham | Muhlenberg County | 763 | 22 | $41k | $84k |
| 42345 | Greenville | Muhlenberg County | 11,440 | 74 | $62k | $139k |
| 42347 | Hartford | Ohio County | 5,829 | 48 | $61k | $135k |
| 42348 | Hawesville | Hancock County | 4,713 | 45 | $57k | $121k |
| 42349 | Horse Branch | Ohio County | 1,962 | 35 | $59k | $89k |
| 42350 | Island | McLean County | 1,342 | 32 | $104k | $168k |
| 42351 | Lewisport | Hancock County | 4,587 | 65 | $76k | $169k |
| 42352 | Livermore | McLean County | 1,955 | 85 | $54k | $143k |
| 42354 | McHenry | Ohio County | 283 | 352 | $66k | $102k |
| 42355 | Maceo | Daviess County | 1,465 | 52 | $60k | $145k |
| 42356 | Maple Mount | Daviess County | 132 | 2,933 | – | – |
| 42361 | Olaton | Ohio County | 425 | 11 | $44k | $89k |
| 42364 | Pellville | Hancock County | PO Box or unique | – | – | – |
| 42366 | Philpot | Daviess County | 5,851 | 67 | $88k | $230k |
| 42367 | Powderly | Muhlenberg County | 949 | 400 | $51k | $100k |
| 42368 | Reynolds Station | Hancock County | 989 | 22 | $76k | $158k |
| 42369 | Rockport | Ohio County | 223 | 74 | $63k | $77k |
| 42370 | Rosine | Ohio County | 16 | 116 | – | – |
| 42371 | Rumsey | McLean County | 472 | 12 | $130k | $164k |
| 42372 | Sacramento | McLean County | 1,389 | 37 | $48k | $103k |
| 42374 | South Carrollton | Muhlenberg County | 124 | 551 | $42k | $123k |
| 42376 | Utica | Daviess County | 6,886 | 70 | $76k | $208k |
| 42377 | West Louisville | Daviess County | PO Box or unique | – | – | – |
| 42378 | Whitesville | Ohio County | 3,513 | 57 | $73k | $181k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.