3101 is the Postal Code/ZIP Code for the of La Unión in the El Salvador Department of La Unión and the Municipality of La Unión.
| Postal Code | 3101 |
| Postal Code Name | La Unión |
| Department | La Unión Department |
| Municipality | La Unión Municipality |
| Timezone | Central Standard Time (CST) |
| Adjacent Postal Codes | 3107 3108 3111 3119 |