| Locality | Post Code |
|---|---|
| Felinfach, Powys | LD3 |
| Felingerrig, Powys | SY20 |
| Fennifach, Powys | LD3 |
| Ffawyddog, Powys | NP8 |
| Fforddlas, Powys | HR3 |
| Ffriddgate, Powys | SY20 8QG |
| Ffrwdgrech, Powys | LD3 |
| Ffynnon Gynydd, Powys | HR3 |
| Figyn, Powys | SY21 9ES |
| Foel, Powys | SY21 |
| Forden, Powys | SY21 |
| Forge, Powys | SY20 |
| Four Crosses, Powys | SY22 |
| Franksbridge, Powys | LD1 5SA |
| Frochas, Powys | SY21 9JD |
| Fron, Powys | SY15, SY21 |
| Garth, Powys | LD4 |
| Garth (Guilsfield), Powys | SY21 |
| Garthbrengy, Powys | LD3 |
| Garthmyl, Powys | SY15 |
| Geuffordd, Powys | SY21 |
| Gladestry, Powys | HR5 |
| Glan-Y-Nant, Powys | SY18 6PQ |
| Glangrwyney, Powys | NP8 |
| Glanrhyd, Powys | SA9 1AG |
| Glanusk, Powys | NP8 1LP |