| Locality | Post Code |
|---|---|
| Iitagawa Iizuka (潟上市) | 018-1504 |
| Iitagawa Kaneyama (潟上市) | 018-1501 |
| Iitagawa Shimoabukawa (潟上市) | 018-1502 |
| Iitagawa Wadaimokawa (潟上市) | 018-1503 |
| Others (潟上市) | 018-1400 |
| Showa Hatchome (潟上市) | 018-1403 |
| Showa Midarebashi (潟上市) | 018-1402 |
| Showa Okubo (潟上市) | 018-1401 |
| Showa Toyokawafunabashi (潟上市) | 018-1413 |
| Showa Toyokawakamiabukawa (潟上市) | 018-1411 |
| Showa Toyokawaokaido (潟上市) | 018-1412 |
| Showa Toyokawaryuge (潟上市) | 018-1415 |
| Showa Toyokawatsukinoki (潟上市) | 018-1414 |
| Showa Toyokawayamada (潟上市) | 018-1416 |
| Tenno (潟上市) | 010-0101, 010-0201 |
| Tenno Osaki (潟上市) | 010-0202 |