| # | Village / Locality | Post Office | PIN Code | Sub District | Type |
|---|---|---|---|---|---|
| 551 | Sihraul | Pipra Bazar SO | 📍 852218 | Pipra | Post Office - PO |
| 552 | Sikrahata | Sikarhatta BO | 📍 847451 | Nirmali | Branch Post Office |
| 553 | Simra | Barail BO | 📍 852110 | Supaul | Branch Post Office |
| 554 | Simrahi | Simrahi Bazar BO | 📍 852111 | Raghopur | Branch Post Office |
| 555 | Simri | Karjain Bazar SO | 📍 852215 | Saraigarh Bhaptiyahi | Post Office - PO |
| 556 | Singiawan | Singihaun BO | 📍 852138 | Kishanpur | Branch Post Office |
| 557 | Siripur | Pratapganj SO Supaul | 📍 852125 | Pratapganj | Post Office - PO |
| 558 | Sisauni | Jobaha BO | 📍 852131 | Marauna | Branch Post Office |
| 559 | Sisauni | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 560 | Siswa | Dighiya BO | 📍 852131 | Kishanpur | Branch Post Office |
| 561 | Sitapur | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 562 | Sitaram Chakla | Jia Ram Raghopur SO | 📍 852111 | Raghopur | Post Office - PO |
| 563 | Sitarampur | Jia Ram Raghopur SO | 📍 852111 | Raghopur | Post Office - PO |
| 564 | Situhar | Pratapganj SO Supaul | 📍 852125 | Pratapganj | Post Office - PO |
| 565 | Sobhankarpur | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 566 | Sohagpur | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 567 | Solhani | Sukhpur SO | 📍 852130 | Supaul | Post Office - PO |
| 568 | Sonapur | Balua Bazar SO | 📍 854339 | Basantpur | Post Office - PO |
| 569 | Sonbarsa | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 570 | Sonpataha | Banania BO | 📍 852105 | Saraigarh Bhaptiyahi | Branch Post Office |
| 571 | Sorhi Malikan | Kharail BO | 📍 852131 | Supaul | Branch Post Office |
| 572 | Sujanpur | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 573 | Sukaila | Ghuran BO | 📍 852131 | Supaul | Branch Post Office |
| 574 | Sukhasan Part in Kishanpur * | Tharbitta SO | 📍 852138 | Saraigarh Bhaptiyahi | Post Office - PO |
| 575 | Sukhasan Part in Saraigarh Bhaptiyahi * | Saraigarh BO | 📍 852105 | Kishanpur | Branch Post Office |
| 576 | Sukhpur Solhani | Barahihat BO | 📍 852130 | Supaul | Branch Post Office |
| 577 | Sukhpur Solhani | Sukhpur SO | 📍 852130 | Supaul | Post Office - PO |
| 578 | Sukmarpur | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 579 | Supaul | Supaul SO | 📍 852131 | Supaul | Post Office - PO |
| 580 | Supaul | Jolahaniya BO | 📍 852131 | Supaul | Branch Post Office |
| 581 | Supaul | Kadampura BO | 📍 852131 | Supaul | Branch Post Office |
| 582 | Supaul | Khokhnaha BO | 📍 852131 | Supaul | Branch Post Office |
| 583 | Supaul | Monga Sihol BO | 📍 852131 | Supaul | Branch Post Office |
| 584 | Supaul | Supaul Bazar SO | 📍 852131 | Supaul | Post Office - PO |
| 585 | SUPAUL BAZAR | SUPAUL BAZAR | 📍 852134 | Supaul | Sub Post Office |
| 586 | Surea urf Siripur | Karjain Bazar SO | 📍 852215 | Basantpur | Post Office - PO |
| 587 | Surjapur | Surjapur BO | 📍 852125 | Pratapganj | Branch Post Office |
| 588 | Surti Patti | Dabhari BO | 📍 852131 | Supaul | Branch Post Office |
| 589 | Takia | Karjain Bazar SO | 📍 852215 | Saraigarh Bhaptiyahi | Post Office - PO |
| 590 | Tekuna | Tekuna BO | 📍 852125 | Pratapganj | Branch Post Office |
| 591 | Telwa | Telwa Situhar BO | 📍 852130 | Supaul | Branch Post Office |
| 592 | Tengri | Balua Bazar SO | 📍 854339 | Chhatapur | Post Office - PO |
| 593 | Thalha | Jia Ram Raghopur SO | 📍 852111 | Raghopur | Post Office - PO |
| 594 | Thalha Garhia | Baljora BO | 📍 852139 | Tribeniganj | Branch Post Office |
| 595 | Tharbitia | Chauhatta BO | 📍 852138 | Kishanpur | Branch Post Office |
| 596 | Tharbitia | Nauwa Bakhar BO | 📍 852138 | Kishanpur | Branch Post Office |
| 597 | Tharbitia | Tharbitta SO | 📍 852138 | Kishanpur | Post Office - PO |
| 598 | Tharhi Bhawanipur | Tarhi Bhawanipur BO | 📍 852218 | Pipra | Branch Post Office |
| 599 | Tharia | Kunauli Bazar SO | 📍 847451 | Nirmali | Post Office - PO |
| 600 | Thumha | Supaul SO | 📍 852131 | Pipra | Post Office - PO |