Sequitor phone extensions
| Main line / control room | 200 |
| Station Manager | 220 |
| Administration | 219 |
| Head of Science Operations | 218 |
| Astronomers office | 223 |
| Telescope and Instrument Operators office | 222 |
| Engineers office | 224 |
| Mechanical Workshop | 226 |
| Electronics Lab | 225 |
| Casino / dining room | 230 |
| Meeting room | 231 |
Chajnantor phone extensions
| Main line (all locations simultaneously) | 299 |
| Control Room | 300 |
| Severs Room | 302 |
| Nasmyth Cabin A | 310 |
| Nasmyth Cabin B | 311 |
| Cassegrain Cabin | 312 |
| Instruments Cabin | 313 |