San Antonio comprises 16 barangays with an estimated population of 99,951. 11 of its barangays (69%) are connectivity dead zones with no recorded cell tower from either the national registry or crowdsourced data.
| Barangay | Population | Towers | Coverage |
|---|---|---|---|
| Buliran | 4,439 | 0 | Dead zone: no towers from any source |
| Cama Juan | 2,251 | 1 | Crowdsourced signal only (no registered tower) |
| Julo | 1,515 | 0 | Dead zone: no towers from any source |
| Lawang Kupang | 1,591 | 0 | Dead zone: no towers from any source |
| Luyos | 5,640 | 0 | Dead zone: no towers from any source |
| Maugat | 3,779 | 0 | Dead zone: no towers from any source |
| Panabingan | 3,793 | 0 | Dead zone: no towers from any source |
| Papaya | 12,980 | 0 | Dead zone: no towers from any source |
| Poblacion | 546 | 0 | Dead zone: no towers from any source |
| San Francisco | 19,065 | 0 | Dead zone: no towers from any source |
| San Jose | 7,841 | 1 | Crowdsourced signal only (no registered tower) |
| San Mariano | 17,624 | 7 | Crowdsourced signal only (no registered tower) |
| Santa Barbara | 7,165 | 0 | Dead zone: no towers from any source |
| Santa Cruz | 1,486 | 8 | Crowdsourced signal only (no registered tower) |
| Santo Cristo | 9,125 | 4 | Crowdsourced signal only (no registered tower) |
| Tikiw | 1,111 | 0 | Dead zone: no towers from any source |