| Place | Post Code |
|---|---|
| Chiengxai, Lak 21 | 16000 |
| Huayhae, Lak 21 | 16000 |
| Khiengtanglae, Lak 21 | 16000 |
| Lak 13, Lak 21 | 16000 |
| Lak 14, Lak 21 | 16000 |
| Lak 16, Lak 21 | 16000 |
| Lak 17, Lak 21 | 16000 |
| Lak 18, Lak 21 | 16000 |
| Lak 19, Lak 21 | 16000 |
| Lak 20, Lak 21 | 16000 |
| Lak 22, Lak 21 | 16000 |
| Lak 23, Lak 21 | 16000 |
| Lak 25, Lak 21 | 16000 |
| Muenluang, Lak 21 | 16000 |
| Nikhom, Lak 21 | 16000 |
| Nongbuathong, Lak 21 | 16000 |
| Nonsaat, Lak 21 | 16000 |
| Phasuam, Lak 21 | 16000 |
| Phinthong, Lak 21 | 16000 |
| Phonexai, Lak 21 | 16000 |
| Thamdin, Lak 21 | 16000 |
| All postal codes in Bachiangchaleunsook | |
|---|---|
| Houaxae, Bachiangchaleunsook | |
| Kaenggnao, Bachiangchaleunsook | |
| Kaengkia, Bachiangchaleunsook | |
| Lak 21, Bachiangchaleunsook | |
| Oudomsouk, Bachiangchaleunsook | |