| # | Village / Locality | Post Office | PIN Code | Sub District | Type |
|---|---|---|---|---|---|
| 401 | Koitor | Kochadhaman BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 402 | Kolaha | Singhia BO | 📍 855107 | Kishanganj | Branch Post Office |
| 403 | Kolaha | Haldikhora BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 404 | Koltha | Maria BO | 📍 855117 | Pothia | Branch Post Office |
| 405 | Konhaiabari | Kanalyabarihat BO | 📍 855107 | Kochadhamin | Branch Post Office |
| 406 | Korat Bangaon | Bangama BO | 📍 855101 | Bahadurganj | Branch Post Office |
| 407 | Kuari | Matiari BO | 📍 855101 | Terhagachh | Branch Post Office |
| 408 | Kuari | Kochadhaman BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 409 | Kudiachhara | Thakurganj SO | 📍 855116 | Thakurganj | Post Office - PO |
| 410 | Kudurbaghi | Churli BO | 📍 855116 | Thakurganj | Branch Post Office |
| 411 | Kuimari | Poth RS BO | 📍 855117 | Pothia | Branch Post Office |
| 412 | Kukur Baghi Milik | Churli BO | 📍 855116 | Thakurganj | Branch Post Office |
| 413 | Kukurbaghi | Churli BO | 📍 855116 | Thakurganj | Branch Post Office |
| 414 | Kulthibari | Poth RS BO | 📍 855117 | Pothia | Branch Post Office |
| 415 | Kumarkhod | Bibiganj BO | 📍 855101 | Dighalbank | Branch Post Office |
| 416 | Kumh Toli | Galgalia SO | 📍 855106 | Thakurganj | Post Office - PO |
| 417 | Kumhartoli | Khodaganj BO | 📍 855108 | Bahadurganj | Branch Post Office |
| 418 | Kumhia | Lohargarha BO | 📍 855101 | Dighalbank | Branch Post Office |
| 419 | Kunjimari | Jirangachhi BO | 📍 855116 | Thakurganj | Branch Post Office |
| 420 | Kurhaila | Bahadurganj SO Kishanganj | 📍 855101 | Bahadurganj | Post Office - PO |
| 421 | Kurhaili | Bibiganj BO | 📍 855101 | Dighalbank | Branch Post Office |
| 422 | Kuri Muni | B.B. Bharatpur BO | 📍 855108 | Thakurganj | Branch Post Office |
| 423 | Kushpara | Singhari BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 424 | Kusiari | Mirjapur BO | 📍 855117 | Pothia | Branch Post Office |
| 425 | Kutti | Kuttigola BO | 📍 855107 | Kochadhamin | Branch Post Office |
| 426 | Lachhmipur | Karhabari BO | 📍 855101 | Dighalbank | Post Office - PO |
| 427 | Lahsora | Bahadurganj SO Kishanganj | 📍 855101 | Bahadurganj | Post Office - PO |
| 428 | Lahugaon Arazi | Thakurganj SO | 📍 855116 | Thakurganj | Post Office - PO |
| 429 | Lakhimara | Chakla Ghat BO | 📍 855107 | Kishanganj | Branch Post Office |
| 430 | Lalbari | Kishanganj SO | 📍 855107 | Kishanganj | Post Office - PO |
| 431 | Landhandara | Thakurganj SO | 📍 855116 | Thakurganj | Post Office - PO |
| 432 | Latkukur Baghi | Churli BO | 📍 855116 | Thakurganj | Branch Post Office |
| 433 | Lator | Singhari BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 434 | Laucha | Laucha BO | 📍 855101 | Bahadurganj | Branch Post Office |
| 435 | Lodhabari | Jhala BO | 📍 855101 | Terhagachh | Branch Post Office |
| 436 | Lodhabari | Raipur BO | 📍 855107 | Pothia | Branch Post Office |
| 437 | Lodhna | Patkoihat BO | 📍 855107 | Kochadhamin | Branch Post Office |
| 438 | Lodhnakhargi | Dhanpatganj BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 439 | Lohagara | Sitalpur BO | 📍 855117 | Pothia | Branch Post Office |
| 440 | Lohagarha | Karhabari BO | 📍 855101 | Dighalbank | Post Office - PO |
| 441 | Lohargarha | Karhabari BO | 📍 855101 | Dighalbank | Post Office - PO |
| 442 | Lohia Kandar | Meharganj BO | 📍 855108 | Bahadurganj | Branch Post Office |
| 443 | Lukundra | Poth RS BO | 📍 855117 | Pothia | Branch Post Office |
| 444 | Mahadeo Dighi | Sontha SO | 📍 855115 | Bahadurganj | Post Office - PO |
| 445 | Mahadha | Modho BO | 📍 855115 | Kochadhamin | Branch Post Office |
| 446 | Mahamari | Dhantola BO | 📍 855101 | Dighalbank | Branch Post Office |
| 447 | Mahammad Nagar | Khodaganj BO | 📍 855108 | Bahadurganj | Branch Post Office |
| 448 | Mahammadpur Bhagal | Kishanganj SO | 📍 855107 | Kishanganj | Post Office - PO |
| 449 | Mahesh Bathna | Mahesh Batna BO | 📍 855101 | Bahadurganj | Post Office - PO |
| 450 | Mahesh Bathna | G.M.Bathna BO | 📍 855107 | Kishanganj | Branch Post Office |