| Location | Zip Code |
| Alaminos | 4001 |
| Bay | 4033 |
| Biņan | 4024 |
| Botocan | 4006 |
| Cabuyao | 4025 |
| Calamba City | 4027 |
| Calauan | 4012 |
| Camp Vicente Lim | 4029 |
| Canlubang | 4028 |
| Cavinti | 4013 |
| Famy | 4021 |
| Kalayaan | 4015 |
| Liliw | 4004 |
| Los Baņos | 4030 |
| Luisiana | 4032 |
| Lumban | 4014 |
| Mabitac | 4020 |
| Magdalena | 4007 |
| Majayjay | 4005 |
| Nagcarlan | 4002 |
| Paete | 4016 |
| Pagsanjan | 4008 |
| Pakil | 4017 |
| Pangil | 4018 |
| Pila | 4010 |
| Rizal | 4003 |
| San Pablo City | 4000 |
| San Pedro | 4023 |
| Santa Cruz | 4009 |
| Santa Maria | 4022 |
| Santa Rosa City | 4026 |
| Siniloan | 4019 |
| University of the Philippines, Los Baņos | 4031 |
| Victoria | 4011 |