| Postal Code | Postal Code Place Name | Province | Canton |
|---|---|---|---|
| 20501 | Atenas | Alajuela | Atenas |
| 20502 | Jesús | Alajuela | Atenas |
| 20503 | Mercedes | Alajuela | Atenas |
| 20504 | San Isidro | Alajuela | Atenas |
| 20505 | Concepción | Alajuela | Atenas |
| 20506 | San José | Alajuela | Atenas |
| 20507 | Santa Eulalia | Alajuela | Atenas |
| 20508 | Escobal | Alajuela | Atenas |