--- title: "Area code 623: Arizona, United States" url: "https://lookvalid.com/area-code/623.md" canonical_url: "https://lookvalid.com/area-code/623" last_updated: "2026-10-23" type: "reference" summary: "Area code 623 serves Arizona, United States. Number formats, numbering rules, a live phone validator and the other codes in Arizona." --- # Area code 623: Arizona, United States Area code 623 serves Arizona, United States. Number formats, numbering rules, a live phone validator and the other codes in Arizona. NANPA lists 311 central office codes (prefixes) in use in area code 623, held by 28 holders across 1 rate center. The largest rate center is PHOENIX, with 311 prefixes (100%). Qwest holds the most prefixes, 97 (31%). 72% of the prefixes are pooled, which means their thousands-blocks can belong to different companies. The FCC unwanted-call data has 2,103 complaints on file for 1,554 numbers in 623, most often filed as "Unwanted Calls". These are consumer reports, not findings. ## Facts - In service since: 1999-03-01 - Time zone: Mountain (M) - Assigned overlays: 602 (1947-01-01), 480 (1999-03-01) - Prefixes in use: 311 - Pooled prefixes: 223 (72%) - Rate centers: 1 - Companies holding prefixes: 28 - Assignment dates on file: 2001-01-18 to 2026-08-07 (164 prefixes) - ZIP codes in its places: 77 ## Rate centers | Rate center | Prefixes | Share | | --- | --- | --- | | PHOENIX | 311 | 100% | ## Carriers | Holder | Prefixes | Share | | --- | --- | --- | | Qwest | 97 | 31% | | T-Mobile USA | 39 | 13% | | Verizon Wireless | 31 | 10% | | Onvoy | 28 | 9% | | New Cingular Wireless PCS | 22 | 7% | | Mcimetro Access Transmission Services | 13 | 4% | | 22 other carriers | 81 | 26% | A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. ## History - 1947-01-01: Area code 602, named as the parent of 623 in the NANPA report, was in service. - 1999-03-01: Area code 623 went into service. ## Nearest area codes The area codes closest to 623, measured between the centers of the ZIP code places they serve, are 520 (about 75 miles), 928 (about 80 miles), 702 (about 253 miles), 725 (about 253 miles) and 760 (about 279 miles). ## ZIP codes 77 ZIP codes fall in places that have a rate center in this area code. The places with the most are Phoenix, AZ (77 ZIP codes). A ZIP code and an area code are unrelated systems, so a ZIP code can sit in more than one area code and an area code spans many ZIP codes. ## Complaints on file 2,103 complaints for 1,554 numbers. Numbers whose latest complaint falls in each year: - 2023: 81 - 2024: 98 - 2025: 110 ## Questions ### Where is area code 623? NANPA assigns area code 623 to Arizona, United States. ### In which state does area code 623 sit? Arizona. 623 is one of 5 area codes the NANPA table assigns to the state. ### Which places does area code 623 cover? The places with the most ZIP codes among the rate centers in 623 are Phoenix, AZ. The rate center list on this page shows all of them. ### Who owns area code 623? NANPA assigns area codes. Within 623, Qwest holds the most prefixes, 97 prefixes or 31%. ### Which time zone does 623 use? The NANPA NPA report lists the time zone for 623 as Mountain (M). ### What year did 623 enter service? The NANPA NPA report gives an in-service date of 1999-03-01, so 623 has been in use since 1999. ### Does area code 623 have an overlay? Yes. 602 (in service 1947-01-01) and 480 (in service 1999-03-01) share the same area with 623, so numbers from all of them are local to each other. ### Which area codes are nearest to 623? The area codes closest to 623, measured between the centers of the ZIP code places they serve, are 520 (about 75 miles), 928 (about 80 miles), 702 (about 253 miles), 725 (about 253 miles) and 760 (about 279 miles). ### How many prefixes does area code 623 have? NANPA's report dated 2026-10-17 lists 311 prefixes in service in 623, spread over 1 rate center and 28 holders. ### Are there complaints about 623 numbers? The FCC data on file has 2,103 complaints for 1,554 numbers in 623. They are unverified consumer reports. A number with no complaints on file is not proven safe. Sources: NANPA central office code report dated 2026-10-17; NANPA NPA report dated 2026-10-18; FCC unwanted-call complaints, data fetched 2026-10-17; ZIP code places from GeoNames (CC BY 4.0).