Gaighat BO is the primary post office registered under PIN code 841231 in Siwan, Bihar. This code sits within the Eastern Postal Region, with 9 offices operating under it.
| Post office | Type | Full name |
|---|---|---|
| Gaighat BO | BO | Branch Post Office |
| Andar SO | SO | Sub Post Office |
| Nadiwan BO | BO | Branch Post Office |
| Nand Pur Amwari BO | BO | Branch Post Office |
| Bhawrajpur BO | BO | Branch Post Office |
| Jaijore BO | BO | Branch Post Office |
| Faridpur BO | BO | Branch Post Office |
| Kherai BO | BO | Branch Post Office |
| Tiyan BO | BO | Branch Post Office |
