| # | Village / Locality | Post Office | PIN Code | Sub District | Type |
|---|---|---|---|---|---|
| 751 | Kalaunjar | Kalaunjar BO | 📍 848125 | Kalyanpur | Branch Post Office |
| 752 | Kaluwara | Nauraga SO | 📍 848102 | Kalyanpur | Post Office - PO |
| 753 | Kalwara | Hayaghat Bilashpur SO | 📍 847301 | Shivaji Nagar | Post Office - PO |
| 754 | Kalwara | Rahua BO | 📍 848133 | Rosera | Branch Post Office |
| 755 | Kalyanpur | Sarairanjan SO | 📍 848127 | Sarairanjan | Post Office - PO |
| 756 | Kalyanpur | Kalyanpur SO Samastipur | 📍 848160 | Bibhutpur | Post Office - PO |
| 757 | Kalyanpur | Kalyanpur Chowk SO | 📍 848302 | Kalyanpur | Post Office - PO |
| 758 | Kalyanpur Basti | Kalyanpur Basti BO | 📍 848502 | Mohiuddinagar | Branch Post Office |
| 759 | Kamapur | Chaita BO | 📍 848132 | Ujiarpur | Branch Post Office |
| 760 | Kamrawan | Kamraon BO | 📍 848114 | Dalsinghsarai | Branch Post Office |
| 761 | Kamtaul | Chakpahar BO | 📍 848122 | Morwa | Branch Post Office |
| 762 | Kamtoul | Madhopur Dighrua SO | 📍 848122 | Tajpur | Post Office - PO |
| 763 | Kamurpur | Sripur Gahar BO | 📍 848117 | Khanpur | Branch Post Office |
| 764 | Kanahauli | Mohiuddin Nagar SO | 📍 848501 | Mohiuddinagar | Post Office - PO |
| 765 | Kancha | Kancha BO | 📍 848503 | Vidyapati Nagar | Branch Post Office |
| 766 | Kanhour | Ashinchak BO | 📍 848114 | Dalsinghsarai | Branch Post Office |
| 767 | Kanjara | Sonsa BO | 📍 848209 | Singhia | Branch Post Office |
| 768 | Kankar | Rahiyar Kochi BO | 📍 848209 | Shivaji Nagar | Branch Post Office |
| 769 | Kankri | Sonsa BO | 📍 848209 | Singhia | Branch Post Office |
| 770 | Kanu Bishunpur | Ilmasnagar SO | 📍 848117 | Khanpur | Post Office - PO |
| 771 | Kapan | Kapan BO | 📍 848236 | Bibhutpur | Branch Post Office |
| 772 | Kapurpatti | Gobarsitha BO | 📍 847301 | Kalyanpur | Branch Post Office |
| 773 | Karachin | Bithan SO | 📍 848207 | Bithan | Post Office - PO |
| 774 | Karahi | Sonsa BO | 📍 848209 | Singhia | Branch Post Office |
| 775 | Karakh | Sakhmohan BO | 📍 848211 | Bibhutpur | Branch Post Office |
| 776 | Karian | Karian BO | 📍 848117 | Shivaji Nagar | Branch Post Office |
| 777 | Karihara | Karihara BO | 📍 848132 | Ujiarpur | Branch Post Office |
| 778 | Karim Nagar | Mohiuddin Nagar SO | 📍 848501 | Mohiuddinagar | Post Office - PO |
| 779 | Karim Nagar | Mohiuddin Nagar R.S SO | 📍 848502 | Mohiuddinagar | Branch Post Office |
| 780 | Karua | Hasanpur [Rusera] BO | 📍 848210 | Khanpur | Branch Post Office |
| 781 | Karwari | Baghra SO Samastipur | 📍 848506 | Mohanpur | Post Office - PO |
| 782 | Kasba Ahar | Tajpur SO Samastipur | 📍 848130 | Tajpur | Post Office - PO |
| 783 | Kasba Tajpur | Tajpur SO Samastipur | 📍 848130 | Tajpur | Post Office - PO |
| 784 | Kashar | Kashore BO | 📍 848133 | Warisnagar | Branch Post Office |
| 785 | Kashipur | Kashipur Samastipur SO | 📍 848101 | Samastipur | Post Office - PO |
| 786 | Kashipur Samastipur SO | Kashipur Samastipur SO | 📍 848104 | Samastipur | Sub Post Office |
| 787 | Kasimchak Arazi | Rajajan BO | 📍 848502 | Mohiuddinagar | Branch Post Office |
| 788 | Katghara | Bhataura BO | 📍 848117 | Shivaji Nagar | Branch Post Office |
| 789 | Katosi | Bithan SO | 📍 848207 | Bithan | Post Office - PO |
| 790 | Kaua | Bajitpur Karnail BO | 📍 848505 | Morwa | Branch Post Office |
| 791 | Kaurahi | Sakhwa BO | 📍 848207 | Bithan | Branch Post Office |
| 792 | Kawai | Kancha BO | 📍 848503 | Vidyapati Nagar | Branch Post Office |
| 793 | Keota | Keota BO | 📍 848114 | Dalsinghsarai | Branch Post Office |
| 794 | Kerai | Kerai BO | 📍 848160 | Bibhutpur | Branch Post Office |
| 795 | Kesho Naraenpur | Keshonarainpur BO | 📍 848504 | Morwa | Branch Post Office |
| 796 | Keshopatti | Muktapur BO | 📍 848102 | Kalyanpur | Branch Post Office |
| 797 | Keshrora | Sakarpura BO | 📍 848205 | Hasanpur | Branch Post Office |
| 798 | Kewas Jagir | Keos Nizamat BO | 📍 848134 | Samastipur | Branch Post Office |
| 799 | KewasNizamat | Keos Nizamat BO | 📍 848134 | Samastipur | Branch Post Office |
| 800 | Khaira | Kubouliram BO | 📍 848131 | Pusa | Branch Post Office |