623 area code — Phoenix, AZ geographic
The 623 area code covers Phoenix, Arizona, Mountain time zone, and dates back to March 1, 1999. It is part of the 480/602/623 overlay complex — these codes share the same territory. Note that porting and VoIP mean a 623 number can be used from anywhere — the code marks where the number was assigned.
310 central-office prefixes are currently active in this code, spread across 27 code-holding carriers. Thousands-block pooling applies to 222 prefixes, so a single prefix can belong to several carriers. All numbers sit in one rate center.
NANPA projects numbering capacity for the 480/602/623 complex to exhaust in 4Q 2056.
Dialing: 10D locally, 10D to other codes (1+10 digit permissible at service provider discretion.).
Practical takeaway: the 623 label narrows geography to Arizona, the prefix narrows it to a locality, and neither authenticates a caller. Verification means calling back through a number you found yourself.
623 was created from 602 in 1999.
Largest localities in 623
| Locality (rate center) | Active prefixes | Also served by |
|---|---|---|
| Phoenix | 310 | 480, 602 |
FAQ
Is 623 a toll-free number?
No. 623 is a geographic code; calls are billed like any other domestic call. Toll-free codes are 800, 833, 844, 855, 866, 877 and 888.
Why do 480 and 623 cover the same place?
They are overlays: when a code runs low on numbers, a new code is added over the same territory instead of splitting it. The 480/602/623 complex shares one service area, and local calls are dialed with 10 digits.
Will 623 run out of numbers?
NANPA's current forecast projects exhaust in 4Q 2056 — decades of capacity remain.
Why am I getting spam calls from 623 numbers?
Scammers spoof recognizable area codes so calls look local or familiar. A displayed 623 number does not prove the call originated there — see our guide to spotting spoofed calls.
Where is a 623 number from?
623 is assigned to Phoenix and surrounding areas of Arizona in the Mountain time zone. The three digits after the area code (the prefix) narrow it down to a rate center.