San Fernando comprises 12 barangays with an estimated population of 20,851. 10 of its barangays (83%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Agtiwa | 1,134 | 0 | Dead zone: no towers from any source |
| Azarga | 1,527 | 0 | Dead zone: no towers from any source |
| Campalingo | 1,970 | 0 | Dead zone: no towers from any source |
| Canjalon | 1,426 | 0 | Dead zone: no towers from any source |
| España | 2,300 | 0 | Dead zone: no towers from any source |
| Mabini | 1,599 | 0 | Dead zone: no towers from any source |
| Mabulo | 1,480 | 0 | Dead zone: no towers from any source |
| Otod | 1,088 | 1 | Crowdsourced signal only (no registered tower) |
| Panangcalan | 865 | 0 | Dead zone: no towers from any source |
| Pili | 1,649 | 0 | Dead zone: no towers from any source |
| Poblacion | 740 | 2 | Crowdsourced signal only (no registered tower) |
| Taclobo | 5,073 | 0 | Dead zone: no towers from any source |