| # | Village / Locality | Post Office | PIN Code | Sub District | Type |
|---|---|---|---|---|---|
| 251 | Jagir Arazi Kaskapur | Banailipatti BO | 📍 854340 | Basantpur | Branch Post Office |
| 252 | Jagur | Bhura BO | 📍 852139 | Tribeniganj | Branch Post Office |
| 253 | Jainagara | Surjapur BO | 📍 852125 | Pratapganj | Branch Post Office |
| 254 | Janardanpur SO | Janardanpur SO | 📍 852133 | Supaul | Sub Post Office |
| 255 | Jarauli | Kunauli Bazar SO | 📍 847451 | Nirmali | Post Office - PO |
| 256 | Jarauli | Cahndpiper BO | 📍 852105 | Pipra | Branch Post Office |
| 257 | Jhahura | Raharia BO | 📍 852105 | Nirmali | Branch Post Office |
| 258 | Jhahura | Gamaharia SO | 📍 852108 | Supaul | Post Office - PO |
| 259 | Jharka | Jharkaha BO | 📍 852132 | Pipra | Branch Post Office |
| 260 | Jhila Dumri | Jhila Dumari BO | 📍 852111 | Saraigarh Bhaptiyahi | Branch Post Office |
| 261 | Jhirwa | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 262 | Jiwachhpur | Gamaharia SO | 📍 852108 | Pipra | Post Office - PO |
| 263 | Jiwachhpur | Pratapganj SO Supaul | 📍 852125 | Chhatapur | Post Office - PO |
| 264 | Jobaha | Jobaha BO | 📍 852131 | Marauna | Branch Post Office |
| 265 | Jobha | Jobha | 📍 852134 | Supaul | Branch Post Office |
| 266 | Jolhaniya | Jolhaniya | 📍 852134 | Supaul | Branch Post Office |
| 267 | Kabiahi | Karjain Bazar SO | 📍 852215 | Saraigarh Bhaptiyahi | Post Office - PO |
| 268 | Kadampura | Kadampura | 📍 852134 | Supaul | Branch Post Office |
| 269 | Kadmaha | Mungraha BO | 📍 847452 | Marauna | Branch Post Office |
| 270 | Kalapatti | Sukhpur SO | 📍 852130 | Supaul | Post Office - PO |
| 271 | Kaleanpur | Bhaptiyahi Bazar SO | 📍 852105 | Saraigarh Bhaptiyahi | Post Office - PO |
| 272 | Kalikapur | Madhubani BO | 📍 852125 | Chhatapur | Branch Post Office |
| 273 | Kamaldaha | Kamaldaha BO | 📍 852105 | Kishanpur | Branch Post Office |
| 274 | Kamalpur | Kamalpur BO | 📍 847451 | Nirmali | Branch Post Office |
| 275 | Kamat Arazi | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 276 | Kamatpur | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 277 | Kamrail | Kamrail BO | 📍 847408 | Marauna | Branch Post Office |
| 278 | Kamrail BO | Kamrail BO | 📍 852133 | Supaul | Branch Post Office |
| 279 | Kanpatti | Sukhpur SO | 📍 852130 | Supaul | Post Office - PO |
| 280 | Kapurah | Birpur SO Supaul | 📍 854340 | Basantpur | Post Office - PO |
| 281 | Karanpatti | Orlaha Bazitpur BO | 📍 852139 | Tribeniganj | Branch Post Office |
| 282 | Karanpur | Karupur BO | 📍 852131 | Supaul | Branch Post Office |
| 283 | Karhari | Karjain Bazar SO | 📍 852215 | Saraigarh Bhaptiyahi | Post Office - PO |
| 284 | Karharwa | Kumiahi BO | 📍 852139 | Tribeniganj | Branch Post Office |
| 285 | Kariho | Kariho BO | 📍 852131 | Supaul | Branch Post Office |
| 286 | Kariho | Kariho | 📍 852134 | Supaul | Branch Post Office |
| 287 | Karjain | Daulatpur BO | 📍 852215 | Raghopur | Branch Post Office |
| 288 | Karjain | Janak Lal Basanpatti BO | 📍 852215 | Raghopur | Branch Post Office |
| 289 | Karjain | Karjain Bazar SO | 📍 852215 | Raghopur | Post Office - PO |
| 290 | Karjain | Korlahi BO | 📍 852215 | Raghopur | Branch Post Office |
| 291 | Karjain | Ratanpura BO | 📍 852215 | Raghopur | Branch Post Office |
| 292 | Karjain | Sripur BO | 📍 852215 | Raghopur | Branch Post Office |
| 293 | Karjain | Tarhi Bazar BO | 📍 852215 | Raghopur | Branch Post Office |
| 294 | Karliana | Surpatganj SO | 📍 852137 | Chhatapur | Post Office - PO |
| 295 | Karupur | Karupur | 📍 852134 | Supaul | Branch Post Office |
| 296 | Katahra | Mohanpur BO | 📍 852137 | Chhatapur | Branch Post Office |
| 297 | Kataia | Nirmali SO Supaul | 📍 847452 | Marauna | Branch Post Office |
| 298 | Kataia | Kataia Mahe BO | 📍 852131 | Supaul | Branch Post Office |
| 299 | Kataia | Bhimnagar Bairrage SO | 📍 854338 | Basantpur | Post Office - PO |
| 300 | Kataia | Sitapur BO | 📍 854339 | Basantpur | Branch Post Office |