| Locality | Postal Code |
|---|---|
| Postal/ZIP Codes in Aimogasta, Arauco | F5310 |
| Postal/ZIP Codes in Arauco, Arauco | F5311 XAB |
| Postal/ZIP Codes in Estación Mazán, Arauco | F5313 |
| Postal/ZIP Codes in Kilometro 891, Arauco | F5313 XAC |
| Postal/ZIP Codes in Kilometro 921, Arauco | F5313 XAD |
| Postal/ZIP Codes in Las Tuscas, Arauco | F5310 XAA |
| Postal/ZIP Codes in Los Baldes, Arauco | F5310 XAD |
| Postal/ZIP Codes in Machigasta, Arauco | F5311 XAC |
| Postal/ZIP Codes in San Antonio, Arauco | F5310 XAB |
| Postal/ZIP Codes in Señor de La Peña, Arauco | F5310 XAE |
| Postal/ZIP Codes in Termas de Santa Teresita, Arauco | F5313 XAA |
| Postal/ZIP Codes in Tinocan, Arauco | F5313 XAB |
| Postal/ZIP Codes in Udpinango, Arauco | F5311 XAA |
| Postal/ZIP Codes in Villa Mazán, Arauco | F5314 |