| Code | Name | Region |
|---|---|---|
| JPTTK | Tsuzuki Ku | |
| JPUBJ | Ube | 35 |
| JPUBY | Ubuyu | 32 |
| JPUHH | Uchihana | 47 |
| JPUCN | Uchinomi | 37 |
| JPUUR | Uchinoura | 46 |
| JPUNU | Uchinourahetsuka | 46 |
| JPUCH | Uchiumi | 45 |
| JPUCU | Uchiura, Fukui | 18 |
| JPTSU | Tsu | 24 |
| JPTUB | Tsubame | 15 |
| JPAAE | Tsubata, Ishikawa | 17 |
| JPTCH | Tsuchiura | 8 |
| JPTUD | Tsuda | 37 |
| JPTUI | Tsui | 28 |
| JPTYN | Tsuiyama | 28 |
| JPTWA | Tsukinokawa | 42 |
| JPTSB | Tsukuba | 8 |
| JPTMI | Tsukumi | 44 |
| JPTUU | Tsukumo | 34 |
| JPGSG | Tsumagoi, Gunma | 10 |
| JPTNA | Tsuna | 28 |
| JPTNI | Tsuneishi | 34 |
| JPTSN | Tsuno | 45 |
| JPTNS | Tsunoshima | 35 |
| JPTRG | Tsuruga | 18 |
| JPTRM | Tsurumi | 14 |
| JPTRU | Tsurumi, Okayama | 33 |
| JPZAA | Tsurumi-ku | 14 |
| JPQTS | Tosu | 41 |
| JPTOT | Totoro | 45 |
| JPTTJ | Tottori | 31 |
| JPTOU | Touyo | 38 |
| JPTWD | Towada | 2 |
| JPTOY | Toyama | 16 |
| JPTOS | Toyamashinko | 16 |
| JPTOA | Toyo | 38 |
| JPYKE | Toyoake | 23 |
| JPTYJ | Toyohama, Aichi | 23 |
| JPTYH | Toyohama, Kagawa | 37 |
| JPTHS | Toyohashi | 23 |
| JPTHA | Toyohira-ku | 1 |
| JPTYW | Toyokawa | 23 |
| JPTYK | Toyonaka | 27 |
| JPTYS | Toyosatu | 25 |
| JPTUS | Toyoshige | 31 |
| JPTYA | Toyota | 23 |
| JPTYR | Toyoura | 33 |
| JPTYC | Toyoyama, Aichi | 23 |
| JPTMG | Tomigusuku, Okinawa | 47 |