| Locality | Postal Code |
|---|---|
| San Martín Zapotitlán, Santa Cruz Muluá | 11004 |
| Santa Cruz Muluá, Santa Cruz Muluá | 11003 |
| Postal Codes in Retalhuleu | |
|---|---|
| Santa Cruz Muluá | San Sebastián |
| San Martín Zapotitlán | San Felipe |
| San Andrés Villa Seca | Retalhuleu |
| Nuevo San Carlos | El Asintal |
| Champerico | |