Phone numbers in Aptos, California
Aptos has 19 phone prefixes in area code 831.
Biggest holders: AT&T (local phone), Onvoy, Teleport Communications America. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 5%
- Local phone company 37%
- Internet / business phone carrier 53%
- Phone company 5%
Every prefix in Aptos
Search the first six digits of a number in this list. If it's here, the number started in Aptos with the carrier shown. If it isn't, check the California page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 831-219 | Teleport Communications America | Internet / business phone carrier | – |
| 831-251 | AT&T Mobility | Mobile carrier | – |
| 831-257 | Onvoy | Internet / business phone carrier | 2016 |
| 831-280 | Commio | Internet / business phone carrier | 2023 |
| 831-318 | Onvoy | Internet / business phone carrier | 2016 |
| 831-531 | MCImetro (Verizon Business) | Internet / business phone carrier | – |
| 831-572 | Utility Telecom Group | Phone company | – |
| 831-603 | Onvoy | Internet / business phone carrier | – |
| 831-607 | IP Horizon | Internet / business phone carrier | – |
| 831-612 | Level 3 (Lumen) | Internet / business phone carrier | – |
| 831-661 | AT&T (local phone) | Local phone company | – |
| 831-662 | AT&T (local phone) | Local phone company | – |
| 831-684 | AT&T (local phone) | Local phone company | – |
| 831-685 | AT&T (local phone) | Local phone company | – |
| 831-687 | AT&T (local phone) | Local phone company | – |
| 831-688 | AT&T (local phone) | Local phone company | – |
| 831-689 | AT&T (local phone) | Local phone company | – |
| 831-708 | Bandwidth | Internet / business phone carrier | – |
| 831-842 | Fractel | Internet / business phone carrier | 2021 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.