San Luis comprises 17 barangays with an estimated population of 52,647. 15 of its barangays (88%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| San Agustin | 861 | 0 | Dead zone: no towers from any source |
| San Carlos | 3,762 | 0 | Dead zone: no towers from any source |
| San Isidro | 5,409 | 0 | Dead zone: no towers from any source |
| San Jose | 6,258 | 0 | Dead zone: no towers from any source |
| San Juan | 5,524 | 0 | Dead zone: no towers from any source |
| San Nicolas | 5,831 | 0 | Dead zone: no towers from any source |
| San Roque | 2,117 | 0 | Dead zone: no towers from any source |
| San Sebastian | 2,350 | 0 | Dead zone: no towers from any source |
| Santa Catalina | 2,421 | 1 | Crowdsourced signal only (no registered tower) |
| Santa Cruz Pambilog | 1,079 | 0 | Dead zone: no towers from any source |
| Santa Cruz Poblacion | 375 | 0 | Dead zone: no towers from any source |
| Santa Lucia | 2,768 | 0 | Dead zone: no towers from any source |
| Santa Monica | 3,213 | 1 | Crowdsourced signal only (no registered tower) |
| Santa Rita | 3,259 | 0 | Dead zone: no towers from any source |
| Santo Niño | 1,496 | 0 | Dead zone: no towers from any source |
| Santo Rosario | 3,385 | 0 | Dead zone: no towers from any source |
| Santo Tomas | 2,539 | 0 | Dead zone: no towers from any source |