Phone numbers in Humboldt, Iowa
Humboldt has 6 phone prefixes in area code 515.
Biggest holders: CenturyLink / Lumen, UScellular, Communications 1 Network. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 67%
- Local phone company 17%
- Phone company 17%
Every prefix in Humboldt
Search the first six digits of a number in this list. If it's here, the number started in Humboldt with the carrier shown. If it isn't, check the Iowa page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 515-332 | CenturyLink / Lumen | Local phone company | – |
| 515-368 | UScellular | Mobile carrier | – |
| 515-604 | Communications 1 Network | Phone company | – |
| 515-849 | AT&T Mobility | Mobile carrier | 2025 |
| 515-890 | Verizon Wireless | Mobile carrier | – |
| 515-902 | T-Mobile (including Sprint) | Mobile carrier | 2018 |
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.