San Fernando comprises 21 barangays with an estimated population of 76,284. 13 of its barangays (62%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Balud | 5,863 | 13 | Verified coverage (NTC + crowdsourced) |
| Balungag | 1,643 | 0 | Dead zone: no towers from any source |
| Basak | 1,456 | 0 | Dead zone: no towers from any source |
| Bugho | 912 | 0 | Dead zone: no towers from any source |
| Cabatbatan | 332 | 0 | Dead zone: no towers from any source |
| Greenhills | 3,226 | 2 | Registered tower only (not crowd-verified) |
| Ilaya | 2,719 | 0 | Dead zone: no towers from any source |
| Lantawan | 2,077 | 0 | Dead zone: no towers from any source |
| Liburon | 1,634 | 0 | Dead zone: no towers from any source |
| Magsico | 1,043 | 0 | Dead zone: no towers from any source |
| Panadtaran | 4,978 | 12 | Verified coverage (NTC + crowdsourced) |
| Pitalo | 7,594 | 10 | Verified coverage (NTC + crowdsourced) |
| Poblacion North | 2,516 | 9 | Verified coverage (NTC + crowdsourced) |
| Poblacion South | 15,086 | 11 | Verified coverage (NTC + crowdsourced) |
| San Isidro | 3,278 | 11 | Crowdsourced signal only (no registered tower) |
| Sangat | 8,125 | 25 | Verified coverage (NTC + crowdsourced) |
| Tabionan | 2,324 | 0 | Dead zone: no towers from any source |
| Tananas | 3,171 | 0 | Dead zone: no towers from any source |
| Tinubdan | 2,460 | 0 | Dead zone: no towers from any source |
| Tonggo | 5,458 | 0 | Dead zone: no towers from any source |
| Tubod | 389 | 0 | Dead zone: no towers from any source |