First three digits · Illinois
ZIP Codes Starting with
54 ZIP codes start with 623, sorted at the Springfield, IL (SCF 625) sectional center (USPS labeling list L005, effective October 1, 2026) in Illinois: 52 residential ZIP codes across 6 counties and 2 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 623 mean?
The first digit, 6, is one of ten national areas (Illinois, Kansas, Missouri and Nebraska). The first three, 623, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 623 to the Springfield, IL (SCF 625) facility. The last two digits pick the delivery area. By residents, the largest town names among the 623 ZIP codes are Quincy, Pittsfield, Mount Sterling, Carthage, Hamilton and Camp Point.
The same facility sorts 4 prefixes, 204 ZIP codes in all: 623, 625, 626, 627.
Where are the 623 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 623
| County | ||||||
|---|---|---|---|---|---|---|
| 62301 | Quincy | Adams County | 30,746 | 2,753 | $52k | $135k |
| 62305 | Quincy | Adams County | 19,036 | 137 | $84k | $214k |
| 62306 | Quincy | Adams County | PO Box or unique | – | – | – |
| 62311 | Augusta | Hancock County | 872 | 18 | $48k | $101k |
| 62312 | Barry | Pike County | 1,931 | 21 | $69k | $98k |
| 62313 | Basco | Hancock County | 382 | 9 | $109k | $133k |
| 62314 | Baylis | Pike County | 530 | 8 | $76k | $160k |
| 62316 | Bowen | Hancock County | 705 | 16 | $61k | $84k |
| 62319 | Camden | Schuyler County | 218 | 6 | $50k | $108k |
| 62320 | Camp Point | Adams County | 2,667 | 33 | $77k | $167k |
| 62321 | Carthage | Hancock County | 3,576 | 21 | $77k | $124k |
| 62323 | Chambersburg | Pike County | 198 | 5 | $93k | $98k |
| 62324 | Clayton | Adams County | 1,196 | 13 | $77k | $97k |
| 62325 | Coatsburg | Adams County | 465 | 25 | $76k | $155k |
| 62326 | Colchester | McDonough County | 2,236 | 29 | $65k | $119k |
| 62329 | Colusa | Hancock County | PO Box or unique | – | – | – |
| 62330 | Dallas City | Hancock County | 1,472 | 17 | $61k | $97k |
| 62334 | Elvaston | Hancock County | 163 | 201 | $39k | $127k |
| 62336 | Ferris | Hancock County | 84 | 525 | $43k | $77k |
| 62338 | Fowler | Adams County | 1,075 | 31 | $92k | $227k |
| 62339 | Golden | Adams County | 970 | 35 | $62k | $126k |
| 62340 | Griggsville | Pike County | 1,673 | 18 | $43k | $100k |
| 62341 | Hamilton | Hancock County | 3,433 | 74 | $62k | $137k |
| 62343 | Hull | Pike County | 611 | 8 | $61k | $95k |
| 62344 | Huntsville | Schuyler County | 60 | 2 | – | $73k |
| 62345 | Kinderhook | Pike County | 359 | 17 | $62k | $68k |
| 62346 | La Prairie | Adams County | 164 | 4 | – | $127k |
| 62347 | Liberty | Adams County | 1,977 | 17 | $94k | $226k |
| 62348 | Lima | Adams County | 204 | 84 | $78k | $88k |
| 62349 | Loraine | Adams County | 517 | 11 | $68k | $88k |
| 62351 | Mendon | Adams County | 1,928 | 26 | $77k | $148k |
| 62352 | Milton | Pike County | 217 | 216 | $51k | $71k |
| 62353 | Mount Sterling | Brown County | 5,066 | 27 | $66k | $152k |
| 62354 | Nauvoo | Hancock County | 1,447 | 40 | $73k | $160k |
| 62355 | Nebo | Pike County | 1,026 | 12 | $66k | $109k |
| 62356 | New Canton | Pike County | 518 | 8 | $69k | $86k |
| 62357 | New Salem | Pike County | 134 | 7 | $81k | $114k |
| 62358 | Niota | Hancock County | 525 | 13 | $62k | $165k |
| 62359 | Paloma | Adams County | 184 | 53 | $51k | – |
| 62360 | Payson | Adams County | 1,605 | 43 | $55k | $148k |
| 62361 | Pearl | Pike County | 301 | 5 | $48k | $81k |
| 62362 | Perry | Pike County | 237 | 40 | $48k | $90k |
| 62363 | Pittsfield | Pike County | 5,561 | 36 | $59k | $118k |
| 62365 | Plainville | Adams County | 464 | 17 | $91k | $163k |
| 62366 | Pleasant Hill | Pike County | 1,450 | 22 | $56k | $82k |
| 62367 | Plymouth | Hancock County | 1,294 | 10 | $58k | $127k |
| 62370 | Rockport | Pike County | 309 | 5 | $116k | $115k |
| 62373 | Sutter | Hancock County | 225 | 5 | $111k | $140k |
| 62374 | Tennessee | Hancock County | 216 | 9 | $79k | $82k |
| 62375 | Timewell | Brown County | 383 | 8 | $77k | $141k |
| 62376 | Ursa | Adams County | 1,276 | 20 | $58k | $178k |
| 62378 | Versailles | Brown County | 863 | 13 | $70k | $151k |
| 62379 | Warsaw | Hancock County | 1,854 | 19 | $62k | $103k |
| 62380 | West Point | Hancock County | 360 | 9 | $75k | $83k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.