| Locality | Post Code |
|---|---|
| Shimogoya (筑西市) | 309-1123 |
| Shimohiratsuka (筑西市) | 308-0066 |
| Shimohoshiya (筑西市) | 309-1122 |
| Shimokawanago (筑西市) | 300-4545 |
| Shimokawashima (筑西市) | 308-0855 |
| Shimokazaki (筑西市) | 308-0826 |
| Shimonakayama (筑西市) | 308-0825 |
| Shimonodono (筑西市) | 308-0844 |
| Shimotakada (筑西市) | 308-0011 |
| Sokajima (筑西市) | 308-0864 |
| Sugaya (筑西市) | 308-0052 |
| Tajuku (筑西市) | 300-4505 |
| Takashima (筑西市) | 308-0807 |
| Takatsu (筑西市) | 300-4534 |
| Takegaki (筑西市) | 300-4543 |
| Tamado (筑西市) | 308-0847 |
| Teraueno (筑西市) | 300-4525 |
| Tokumochi (筑西市) | 308-0816 |
| Tonozuka (筑西市) | 308-0053 |
| Tsuiji (筑西市) | 300-4531 |
| Tsuji (筑西市) | 308-0103 |
| Tsukahara (筑西市) | 308-0822 |
| Uchiyodo (筑西市) | 300-4507 |
| Ueno (筑西市) | 308-0129 |
| Warabi (筑西市) | 308-0824 |
| Yabe (筑西市) | 308-0006 |