Phone numbers in Monterey, Louisiana
Monterey has 3 phone prefixes in area code 318.
Biggest holders: AT&T Mobility, AT&T (local phone). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 67%
- Local phone company 33%
Every prefix in Monterey
Search the first six digits of a number in this list. If it's here, the number started in Monterey with the carrier shown. If it isn't, check the Louisiana page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 318-386 | AT&T (local phone) | Local phone company | – |
| 318-421 | AT&T Mobility | Mobile carrier | 2002 |
| 318-804 | AT&T Mobility | Mobile carrier | 2022 |
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.