Mashi Local Government Area in Katsina State uses postal codes is 823102.
Here are the postal codes for the towns and districts in Mashi:
| Place/Area | Postal code |
| Shargalle | 823102 |
| Sonkaya | 823102 |
| Tamilo | 823102 |
| Tudu | 823102 |
| Yamal | 823102 |
| Yar Daddo | 823102 |
| Dokawa | 823102 |
| Gallu | 823102 |
| Jigawa | 823102 |
| Karawa | 823102 |
| Korau | 823102 |
| Majigiri | 823102 |
| Mashi | 823102 |
| Morawa | 823102 |
| S-Rijiya | 823102 |
| Saye | 823102 |
| Agalla | 823102 |
| Badauri | 823102 |
| Bamle | 823102 |
| Birnin Kuka | 823102 |
| Dindiyel | 823102 |
| Doguru | 823102 |