Opobo–Nkoro Local Government Area in Rivers State uses the postal code 503103.
Here is the postal code for Opobo–Nkoro:
| Place/Area | Postal code |
| Epelema | 503103 |
| Ikwata | 503103 |
| Iloma | 503103 |
| Iwoama | 503103 |
| Job-Ama | 503103 |
| Kalaibiama | 503103 |
| Kalasunju | 503103 |
| Minima | 503103 |
| Nkoro | 503103 |
| Obo- Town | 503103 |
| Okorobo -Ile | 503103 |
| Olam – Nkoro | 503103 |
| Olum | 503103 |
| Opum | 503103 |
| Queens Town | 503103 |