| Locality | Post Code |
|---|---|
| Allenwood, Union | 17810 |
| Brook Park, Union | 17837 |
| Buffalo X Roads, Union | 17837 |
| Cherry Run, Union | 17885 |
| College Park, Union | 17837 |
| Cowan, Union | 17844 |
| Dice, Union | 17844 |
| Dry Valley, Union | 17889 |
| East Buffalo, Union | 17837 |
| Elimsport, Union | 17810 |
| Fairville, Union | 17837 |
| Foresthill, Union | 17844 |
| Gleniron, Union | 17845 |
| Gregg, Union | 17810 |
| Hartleton, Union | 17829 |
| Kelly, Union | 17837 |
| Kelly Point, Union | 17837 |
| Kelly X Roads, Union | 17837 |
| Laurel Park, Union | 17845 |
| Laurelton, Union | 17835 |
| Lewisburg, Union | 17837 |
| Linntown, Union | 17837 |
| Lochiel, Union | 17837 |
| Mazeppa, Union | 17837 |
| Mifflinburg, Union | 17844 |
| Millmont, Union | 17845 |