| # | Village / Locality | Post Office | PIN Code | Sub District | Type |
|---|---|---|---|---|---|
| 601 | Kamalpur | Kajraili BO | 📍 812005 | Nathnagar | Branch Post Office |
| 602 | Kamarganj | Jahagira BO | 📍 813213 | Sultanganj | Branch Post Office |
| 603 | Kamarpur | Kathara BO | 📍 813213 | Sultanganj | Branch Post Office |
| 604 | Kamarpur Arazi | Udhadih BO | 📍 813213 | Sultanganj | Branch Post Office |
| 605 | Kamlakund | Kamlakund BO | 📍 853205 | Ismailpur | Branch Post Office |
| 606 | Kaneri | Chandpur BO | 📍 813105 | Jagdishpur | Branch Post Office |
| 607 | Kangali chauki | Salempurtola BO | 📍 813209 | Pirpainti | Branch Post Office |
| 608 | Kangalichak | Salempurtola BO | 📍 813209 | Pirpainti | Branch Post Office |
| 609 | Kanjhia | Nathnagar SO | 📍 812006 | Nathnagar | Post Office - PO |
| 610 | Kanjhia Nurpur | Mirzapur BO | 📍 812004 | Nathnagar | Branch Post Office |
| 611 | Kapsena | Kapsona BO | 📍 813108 | Shahkund | Branch Post Office |
| 612 | Karahara Basantpur Milik | Ekchari SO | 📍 813204 | Colgong | Post Office - PO |
| 613 | Karahara Basdeopur Milik | Ekchari SO | 📍 813204 | Colgong | Post Office - PO |
| 614 | Karaila | Nathnagar SO | 📍 812006 | Nathnagar | Post Office - PO |
| 615 | Karampur | Mirjanhat SO | 📍 812005 | Jagdishpur | Post Office - PO |
| 616 | Karanpur | Ranuchakmakandpur BO | 📍 812004 | Nathnagar | Branch Post Office |
| 617 | Karanpur | Khaira BO | 📍 812006 | Shahkund | Branch Post Office |
| 618 | Karanpur | Kiranpur BO | 📍 813108 | Shahkund | Branch Post Office |
| 619 | Karanpur | Karia BO | 📍 813204 | Shahkund | Branch Post Office |
| 620 | Karharia | Harnathpur BO | 📍 812006 | Shahkund | Branch Post Office |
| 621 | Karharia | Kasimpur BO | 📍 813105 | Goradih | Branch Post Office |
| 622 | Karharia | Mohiuddivpur BO | 📍 813105 | Jagdishpur | Branch Post Office |
| 623 | Karharia | Karaharia BO | 📍 813201 | Sultanganj | Branch Post Office |
| 624 | Karikado | Mathurapur SO Bhagalpur | 📍 813222 | Colgong | Post Office - PO |
| 625 | Karimachak | Karik Bazar SO | 📍 853202 | Kharik | Post Office - PO |
| 626 | Karimachak | Jamuuia BO | 📍 853202 | Naugachhia | Branch Post Office |
| 627 | Karimchak | Ekchari SO | 📍 813204 | Sonhaula | Post Office - PO |
| 628 | Karimpur | Sanhouli BO | 📍 812005 | Jagdishpur | Branch Post Office |
| 629 | Kasaiabag | Bhagalpur HO | 📍 812001 | Sabour | Head Post Office - H |
| 630 | Kasba | Sultanganj SO Bhagalpur | 📍 813213 | Sultanganj | Post Office - PO |
| 631 | Kasba kherhi | Sahkund SO | 📍 813108 | Shahkund | Post Office - PO |
| 632 | Kashipur | Kiranpur BO | 📍 813108 | Shahkund | Branch Post Office |
| 633 | Kasil | Murhan BO | 📍 813205 | Goradih | Branch Post Office |
| 634 | Kasimpur | Kasimpur BO | 📍 813105 | Goradih | Branch Post Office |
| 635 | Kasri | Kasri BO | 📍 813203 | Colgong | Branch Post Office |
| 636 | Kastikri | Asarganj SO | 📍 813201 | Sultanganj | Post Office - PO |
| 637 | Kathara | Kathara BO | 📍 813213 | Sultanganj | Branch Post Office |
| 638 | Kathi | Tetripakra BO | 📍 853204 | Naugachhia | Branch Post Office |
| 639 | Kathwan | Harnathpur BO | 📍 812006 | Shahkund | Branch Post Office |
| 640 | Kazi Bhatu Milik | Agarpur BO | 📍 813210 | Goradih | Branch Post Office |
| 641 | Kazi Koraia | Ishapur Chorhar BO | 📍 853202 | Kharik | Branch Post Office |
| 642 | Kedarpur | Ghogha SO | 📍 813205 | Goradih | Post Office - PO |
| 643 | Kelapur | Kajraili BO | 📍 812005 | Nathnagar | Branch Post Office |
| 644 | Kelapur | Sahjadpur BO | 📍 813108 | Jagdishpur | Branch Post Office |
| 645 | Keshopur | Chaknathu BO | 📍 813204 | Sonhaula | Branch Post Office |
| 646 | Kesopur | Rataupurmaikpur BO | 📍 813108 | Shahkund | Branch Post Office |
| 647 | Kesopur Mukhar | Bakchappar BO | 📍 813108 | Shahkund | Branch Post Office |
| 648 | Kewanchak | Chaknathu BO | 📍 813204 | Sonhaula | Branch Post Office |
| 649 | Khagra | Khajra BO | 📍 853204 | Naugachhia | Branch Post Office |
| 650 | Khagra Arazi | Khajra BO | 📍 853204 | Naugachhia | Branch Post Office |