Phone numbers in Sunnyside, Washington
Sunnyside has 15 phone prefixes in area code 509.
Biggest holders: T-Mobile (including Sprint), CenturyLink / Lumen, AT&T Mobility. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 60%
- Local phone company 20%
- Internet / business phone carrier 20%
Every prefix in Sunnyside
Search the first six digits of a number in this list. If it's here, the number started in Sunnyside with the carrier shown. If it isn't, check the Washington page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 509-274 | AT&T Mobility | Mobile carrier | – |
| 509-305 | T-Mobile (including Sprint) | Mobile carrier | – |
| 509-391 | T-Mobile (including Sprint) | Mobile carrier | – |
| 509-439 | Verizon Wireless | Mobile carrier | – |
| 509-502 | Verizon Wireless | Mobile carrier | 2019 |
| 509-515 | Charter / Spectrum | Internet / business phone carrier | 2007 |
| 509-643 | Level 3 (Lumen) | Internet / business phone carrier | 2002 |
| 509-712 | T-Mobile (including Sprint) | Mobile carrier | 2021 |
| 509-790 | Skyetel | Internet / business phone carrier | – |
| 509-830 | UScellular | Mobile carrier | – |
| 509-831 | UScellular | Mobile carrier | – |
| 509-836 | CenturyLink / Lumen | Local phone company | – |
| 509-837 | CenturyLink / Lumen | Local phone company | – |
| 509-839 | CenturyLink / Lumen | Local phone company | – |
| 509-840 | AT&T Mobility | Mobile carrier | – |
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.