| Place | Post Code |
|---|---|
| Houayhao, Houaykop | 02000 |
| Houayhia, Houaykop | 02000 |
| Houaykop, Houaykop | 02000 |
| Nakhoa, Houaykop | 02000 |
| Nale, Houaykop | 02000 |
| Namnene, Houaykop | 02000 |
| Nongheo, Houaykop | 02000 |
| Paknene, Houaykop | 02000 |
| Salouang, Houaykop | 02000 |
| Sompoy, Houaykop | 02000 |
| All postal codes in May | |
|---|---|
| Houaykop, May | |
| Kounglouk, May | |
| Nalam, May | |
| Namnga, May | |
| Pakphae, May | |
| Palan, May | |
| Phialo, May | |
| Phonxai, May | |
| Poungyang, May | |
| Sophoun, May | |