| Locality | Postal Code |
|---|---|
| Postal/ZIP Codes in Yahata (筑西市) | 309-1112 |
| Postal/ZIP Codes in Yamazaki (筑西市) | 308-0865 |
| Postal/ZIP Codes in Yanagashima (筑西市) | 309-1121 |
| Postal/ZIP Codes in Yanagi (筑西市) | 309-1113 |
| Postal/ZIP Codes in Yanaka (筑西市) | 308-0056 |
| Postal/ZIP Codes in Yawara (筑西市) | 300-4535 |
| Postal/ZIP Codes in Yokoshima (筑西市) | 308-0802 |
| Postal/ZIP Codes in Yokotsuka (筑西市) | 309-1116 |
| Postal/ZIP Codes in Yomogita (筑西市) | 309-1102 |
| Postal/ZIP Codes in Yono (筑西市) | 308-0838 |
| Postal/ZIP Codes in Yoshida (筑西市) | 300-4542 |