| Locality | Post Code |
|---|---|
| Bancroft, Shiawassee | 48414 |
| Byron, Shiawassee | 48418 |
| Corunna, Shiawassee | 48817 |
| Durand, Shiawassee | 48429 |
| Elsie, Shiawassee | 48831 |
| Henderson, Shiawassee | 48841 |
| Laingsburg, Shiawassee | 48848 |
| Lennon, Shiawassee | 48449 |
| Morrice, Shiawassee | 48857 |
| New Lothrop, Shiawassee | 48460 |
| Ovid, Shiawassee | 48866 |
| Owosso, Shiawassee | 48867 |
| Perry, Shiawassee | 48872 |
| Shaftsburg, Shiawassee | 48882 |
| Vernon, Shiawassee | 48476 |