| Locality | Post Code |
|---|---|
| Country Club Heights, Mason | 41056 |
| Dover, Mason | 41034 |
| Germantown, Mason | 41044 |
| Helena, Mason | 41055 |
| Mayslick, Mason | 41055 |
| Maysville, Mason | 41056 |
| Mill Creek, Mason | 41055 |
| Minerva, Mason | 41062 |
| Moranburg, Mason | 41056 |
| Murphysville, Mason | 41056 |
| Needmore, Mason | 41055 |
| Orangeburg, Mason | 41056 |
| Plumville, Mason | 41056 |
| Rectorville, Mason | 41056 |
| Sardis, Mason | 41056 |
| Shannon, Mason | 41055 |
| Washington, Mason | 41096 |
| Wedonia, Mason | 41055 |