San Carlos City comprises 18 barangays with an estimated population of 116,762. 9 of its barangays (50%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Bagonbon | 4,059 | 0 | Dead zone: no towers from any source |
| Barangay I (Pob.) | 8,720 | 4 | Crowdsourced signal only (no registered tower) |
| Barangay II (Pob.) | 7,527 | 8 | Crowdsourced signal only (no registered tower) |
| Barangay III (Pob.) | 1,180 | 4 | Crowdsourced signal only (no registered tower) |
| Barangay IV (Pob.) | 2,500 | 8 | Crowdsourced signal only (no registered tower) |
| Barangay V (Pob.) | 3,548 | 6 | Crowdsourced signal only (no registered tower) |
| Barangay VI (Pob.) | 1,183 | 0 | Dead zone: no towers from any source |
| Buluangan | 9,886 | 1 | Crowdsourced signal only (no registered tower) |
| Codcod | 7,846 | 0 | Dead zone: no towers from any source |
| Ermita | 2,329 | 0 | Dead zone: no towers from any source |
| Guadalupe | 10,648 | 1 | Crowdsourced signal only (no registered tower) |
| Nataban | 2,144 | 0 | Dead zone: no towers from any source |
| Palampas | 20,831 | 4 | Crowdsourced signal only (no registered tower) |
| Prosperidad | 3,750 | 0 | Dead zone: no towers from any source |
| Punao | 6,049 | 0 | Dead zone: no towers from any source |
| Quezon | 10,009 | 0 | Dead zone: no towers from any source |
| Rizal | 13,176 | 21 | Crowdsourced signal only (no registered tower) |
| San Juan | 1,377 | 0 | Dead zone: no towers from any source |