| Locality | Postal Code |
|---|---|
| Ainoyamachi (常総市) | 303-0002 |
| Araigimachi (常総市) | 303-0016 |
| Azumacho (常総市) | 303-0011 |
| Baba (常総市) | 300-2748 |
| Babashinden (常総市) | 300-2733 |
| Chosukemachi (常総市) | 303-0015 |
| Daibo (常総市) | 300-2716 |
| Fukujimachi (常総市) | 300-2501 |
| Furumagi (常総市) | 300-2724 |
| Furumaginumashinden (常総市) | 300-2725 |
| Furumagishinden (常総市) | 300-2731 |
| Gorobeeshindemmachi (常総市) | 300-2524 |
| Hanashimamachi (常総市) | 300-2511 |
| Hanyumachi (常総市) | 300-2513 |
| Harajuku (常総市) | 300-2702 |
| Heimachi (常総市) | 303-0017 |
| Heinai (常総市) | 300-2714 |
| Hyomachi (常総市) | 303-0014 |
| Izaemonshindemmachi (常総市) | 300-2525 |
| Jojamachi (常総市) | 300-2502 |
| Jukkamachi (常総市) | 303-0018 |
| Kawasakimachi (常総市) | 300-2503 |
| Konoyama (常総市) | 300-2746 |
| Konoyamashinden (常総市) | 300-2732 |
| Kossho (常総市) | 300-2741 |
| Koyamadomachi (常総市) | 303-0006 |