| Locality | Post Code |
|---|---|
| Augusta, Saint Charles | 63332 |
| Black Walnut, Saint Charles | 63301 |
| Cottleville, Saint Charles | 63338 |
| Dardenne, Saint Charles | 63366 |
| Dardenne Prairie, Saint Charles | 63368 |
| Defiance, Saint Charles | 63341 |
| Femme Osage, Saint Charles | 63332 |
| Flinthill, Saint Charles | 63346 |
| Foristell, Saint Charles | 63348 |
| Gilmore, Saint Charles | 63385 |
| Harvester, Saint Charles | 63303 |
| Josephville, Saint Charles | 63385 |
| Kampville, Saint Charles | 63301 |
| Kampville Beach, Saint Charles | 63301 |
| Kampville Court, Saint Charles | 63301 |
| Lake Saint Louis, Saint Charles | 63367 |
| Machens, Saint Charles | 63373 |
| Matson, Saint Charles | 63341 |
| New Melle, Saint Charles | 63365 |
| O Fallon, Saint Charles | 63366, 63368 |
| Orchard Farm, Saint Charles | 63301 |
| Portage Des Sioux, Saint Charles | 63373 |
| Saint Charles, Saint Charles | 63301, 63302, 63303, 63304 |
| Saint Paul, Saint Charles | 63366 |
| Saint Peters, Saint Charles | 63303, 63304, 63366, 63376 |
| Schluersburg, Saint Charles | 63332 |