| Locality | Postal Code |
|---|---|
| Postal/ZIP Codes in Cañada San Jorge, Unión | 021104 |
| Postal/ZIP Codes in Cañada Santa Maria, Unión | 021102 |
| Postal/ZIP Codes in Centro, Unión | 021101 |
| Postal/ZIP Codes in Cerro Monte Alto, Unión | 021103 |
| Postal/ZIP Codes in Cobas Kue, Unión | 021103 |
| Postal/ZIP Codes in Hugua Mojon, Unión | 021104 |
| Postal/ZIP Codes in Maria Goretti, Unión | 021101 |
| Postal/ZIP Codes in Potrerito, Unión | 021104 |
| Postal/ZIP Codes in San Antonio, Unión | 021104 |
| Postal/ZIP Codes in San Blas, Unión | 021105 |
| Postal/ZIP Codes in San Jose, Unión | 021101 |
| Postal/ZIP Codes in San Roque, Unión | 021101, 021103 |
| Postal/ZIP Codes in Santa Catalina, Unión | 021101, 021102 |
| Postal/ZIP Codes in Santo Domingo, Unión | 021102 |