San Quintin comprises 6 barangays with an estimated population of 4,634. 5 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 |
|---|---|---|---|
| Labaan | 830 | 0 | Dead zone: no towers from any source |
| Palang | 539 | 0 | Dead zone: no towers from any source |
| Pantoc | 501 | 0 | Dead zone: no towers from any source |
| Poblacion | 702 | 0 | Dead zone: no towers from any source |
| Tangadan | 1,108 | 1 | Crowdsourced signal only (no registered tower) |
| Villa Mercedes | 954 | 0 | Dead zone: no towers from any source |