| Locality | Post Code |
|---|---|
| Ackley, Butler | 50601 |
| Allison, Butler | 50602 |
| Aplington, Butler | 50604 |
| Aredale, Butler | 50605 |
| Austinville, Butler | 50608 |
| Bristow, Butler | 50611 |
| Clarksville, Butler | 50619 |
| Dumont, Butler | 50625 |
| Fern, Butler | 50665 |
| Greene, Butler | 50636 |
| Kesley, Butler | 50649 |
| New Hartford, Butler | 50660 |
| Packard, Butler | 50619 |
| Parkersburg, Butler | 50665 |
| Plainfield, Butler | 50666 |
| Powersville, Butler | 50636 |
| Shell Rock, Butler | 50670 |
| Sinclair, Butler | 50665 |