If your phone lights up with a number starting in 623, it is coming from the west side of Phoenix, Arizona. The area code for 623 covers the West Valley — Glendale, Peoria, Surprise, Goodyear, Avondale, Buckeye, and the smaller towns around them. It has been around since 1999, and since 2023 it shares the whole Phoenix metro with area codes 480 and 602. Here is where it is, how to dial it, what time it keeps, and what to do when an unknown 623 number calls.
Where Is the 623 Area Code?
The 623 area code serves the western and northwestern suburbs of the Phoenix metropolitan area, the part locals call the West Valley. Every 623 number sits inside Maricopa County, and the whole code is a single rate center — Phoenix — which is why calls across the Valley count as local, not long distance.
Before 2023, 623 had its own patch of the map. That changed in September 2023, when regulators folded 602, 480, and 623 into one overlay covering the entire Phoenix metro. A new phone line in Glendale can now be given a 480 or 602 number, and a new line in Scottsdale can get a 623 number. The code still points to the West Valley in people’s minds, but on paper the three codes now cover the same ground.
The cities and towns in area code 623
| Place | Known for |
|---|---|
| Glendale | State Farm Stadium, home of the Arizona Cardinals, and Camelback Ranch spring training |
| Peoria | Peoria Sports Complex, spring training home of the Padres and Mariners |
| Surprise | Surprise Stadium, spring training home of the Royals and Rangers |
| Goodyear | Goodyear Ballpark, spring training home of the Guardians and Reds |
| Avondale | Phoenix Raceway, which hosts two NASCAR weekends a year |
| Buckeye | A fast-growing suburb on the Valley’s far western edge |
| Sun City | The West Valley’s big retirement community |
| Sun City West | Retirement living next door to Sun City |
| El Mirage | A smaller West Valley city beside Glendale |
| Youngtown | One of the Valley’s oldest small towns |
| Litchfield Park | A quiet planned community west of Phoenix |
| Tolleson | A small industrial city on the Valley’s west side |
North Phoenix north of Union Hills Drive was also in 623 when the code was created, and the code’s exchanges still include parts of Phoenix itself. If you are not sure whether a number is a 623 number, the area code is the only thing that matters — the city does not change what you dial.
What Time Zone Is Area Code 623 In?
Area code 623 runs on Mountain Standard Time, UTC-7, all year. Arizona does not observe daylight saving time, so the clock in the West Valley never moves forward in spring or back in fall. That makes 623 easy to read once you know the trick: it matches Pacific Time in the summer and Mountain Time in the winter.
What time is it in 623 when it is noon there?
| If it is noon in 623 | March to November | November to March |
|---|---|---|
| Eastern Time (New York) | 3:00 PM | 2:00 PM |
| Central Time (Chicago) | 2:00 PM | 1:00 PM |
| Mountain Time (Denver) | 1:00 PM | 12:00 PM |
| Pacific Time (Los Angeles) | 12:00 PM | 11:00 AM |
The table works because Arizona stays put while the rest of the country shifts. From March to November, most of the United States is on daylight saving time, so the gap between Phoenix and New York grows to three hours. In winter it shrinks back to two. If you are calling a business in Glendale from the East Coast, mid-morning your time is still early morning theirs — aim for after 11 AM Eastern and you will catch them after 9 AM local.
How to Dial a 623 Number
Since August 12, 2023, ten-digit dialing is mandatory across the Phoenix metro. You dial the area code plus the seven-digit number for every call, even to the house across the street. Seven-digit dialing no longer connects — you will hear a recording telling you to redial with the area code.
| Calling from | Dial this |
|---|---|
| Inside the Phoenix metro (any 623, 480, or 602 number) | 623 + seven-digit number |
| Elsewhere in the United States | 1 + 623 + seven-digit number |
| Outside the United States | Your country’s exit code + 1 + 623 + seven-digit number |
That is the whole rule. There is no special prefix for the West Valley, and no extra digit for calling between the three Phoenix area codes. The 1 before the area code on long-distance calls is the US country code, not part of the area code itself.
The 2023 Overlay: Why 623 Shares Phoenix With 480 and 602
For 24 years, the Phoenix map was simple: 602 in the middle, 480 in the east, 623 in the west. The map broke because 480 and 602 were running out of numbers. By October 2020, the North American Numbering Plan Administrator forecast that 480 would exhaust in the first quarter of 2024, and 602 two years after that. Area code 623, meanwhile, was nowhere near full — in 2021 it had only 299 assigned central office codes, against more than 700 in each of the other two, and its exhaustion was not forecast until 2069.
Rather than carve up the map again, the Arizona Corporation Commission approved a boundary-elimination overlay on November 9, 2021. The old borders came down, and the three codes now share one territory of about four million people. New numbers are drawn mostly from 623, simply because it has the most spare codes. The overlay went live on September 12, 2023, after a six-month permissive dialing period that started February 11, 2023.
What does that mean for you? Two things. First, the area code no longer tells you exactly where someone lives in Phoenix — your neighbour can have 480 while you have 623. Second, if you ask a carrier for a new 623 number for your business, they may or may not have one free. The code is the one with the most room, but under an overlay no carrier can promise a specific area code for a new line. If the number itself matters to you, ask for 623 by name and be ready to take what is available.
A Short History of the 623 Area Code
| When | What happened |
|---|---|
| 1947 | Arizona gets a single area code, 602, for the whole state |
| March 19, 1995 | Area code 520 splits off for Arizona outside the Phoenix metro |
| December 18, 1998 | The Arizona Corporation Commission approves a three-way split of 602 |
| March 1, 1999 | Area code 623 goes into service for the West Valley; 480 starts the same day for the East Valley |
| April 1, 1999 | Permissive dialing of the new codes begins |
| November 9, 2021 | The Commission approves the boundary-elimination overlay for 602, 480, and 623 |
| February 11, 2023 | Six-month permissive ten-digit dialing period starts for 602 and 623 |
| August 12, 2023 | Ten-digit dialing becomes mandatory across the Phoenix metro |
| September 12, 2023 | The three-code overlay goes live; the old 1999 borders are gone |
A word on the dates, because the guides online disagree. Some sites say 623 was created on January 16, 1999, and others say April 1, 1999. The in-service date in the North American Numbering Plan Administrator’s own records is March 1, 1999 — that is the date this article uses. April 1 is when permissive dialing of the new codes started, which is where the confusion comes from. One more bit of trivia: 556 was considered for the West Valley code before 623 was chosen.
623 vs 480 vs 602: What Is the Difference?
Since the 2023 overlay, the honest answer is: not much. All three codes cover the same place, use the same dialing rules, and keep the same time. The differences are history and how full each code is.
| 623 | 480 | 602 | |
|---|---|---|---|
| Original territory | West Valley | East Valley | Central Phoenix |
| Went into service | March 1, 1999 | March 1, 1999 | 1947 |
| Time zone | MST, UTC-7, no DST | MST, UTC-7, no DST | MST, UTC-7, no DST |
| Dialing | 10 digits, mandatory | 10 digits, mandatory | 10 digits, mandatory |
| How full it is | 312 of 800 codes assigned (39%) | More than 700 codes assigned | More than 700 codes assigned |
| Running out? | Not forecast until 2069 | Was forecast for early 2024 | Was forecast for 2026 |
The fullness figures come from the numbering administrator’s files: as of October 2026, 623 has 312 of its 800 possible central office codes assigned, held by 28 carriers, with 55 new codes assigned since 2020 and no relief planning in progress. The code with the most room is also the code new Phoenix numbers are most likely to come from. If you want the fuller story on its eastern twin, our guide to the 480 phone code covers the same history from the East Valley side.
What Do the Three Digits After 623 Mean?
A phone number has three parts: the area code (623), the central office code (the next three digits), and the line number (the last four). The central office code, also called the exchange, once pointed to a specific telephone exchange building. Today it mostly points to a carrier and a block of numbers — and with number pooling, a single code’s 10,000 numbers are often shared between carriers.
What the exchange cannot do is name the person behind the number. No free lookup can reliably tell you who owns a 623 number, because numbers are ported between carriers and the records are not public. Any site that promises to name the owner of a number for free is selling you something, not informing you.
Is 623 a Toll-Free Area Code?
No. Area code 623 is a normal geographic area code, not a toll-free code like 800, 888, or 877. Calls inside the Phoenix metro are local because the whole Valley is one rate center, so you will not pay long-distance charges calling from one part of the metro to another. But the code itself carries no promise that a call is free — a 623 number can still belong to a business that charges for its services, and a call to it from outside the Valley is a normal long-distance call.
Can I Keep My 623 Number If I Move?
Usually, yes. In the United States you can generally keep your mobile number when you switch carriers or move, and your new carrier handles the porting. Landlines are trickier — whether a number can move depends on the rate center, and moving far away can mean giving the number up. The practical rule is simple: ask your carrier before you move, and do not cancel the old service until the port is done. Cancelling first can release the number back into the pool, and getting it back is rarely possible.
How to Get a 623 Phone Number
You get a 623 number the same way you get any local number: through a phone carrier or a virtual-number provider. Ask for a West Valley number and the carrier will offer whatever 623 inventory it holds. Two catches are worth knowing. First, under the overlay, a new line in the West Valley can be assigned 480 or 602 instead — no carrier can guarantee a 623 number for a fresh line. Second, if you already own a 623 number and move it to a new provider, porting keeps the number. Most providers will set the number up in minutes; the number itself is the slow part, because it depends on what is free that day.
Unknown 623 Number Calling? What to Do
A 623 number on your screen means the caller is using a West Valley number — or pretending to. Scammers can fake any caller ID, including a local one, so the area code alone proves nothing about who is really calling. The Federal Trade Commission’s advice is blunt: do not trust your caller ID.
If an unknown 623 number calls, let it go to voicemail. A real caller with real business will leave a message you can check. If you do answer and the caller pressures you — for money, gift cards, account access, or a verification code — hang up. Real banks, government agencies, and phone companies do not ask for those things on an unexpected call, and they do not threaten to cut off your service within hours.
Never call back a number left in a suspicious voicemail. Look the organisation up yourself and call the number on its official website. If you think the call was a scam, report it to the Federal Trade Commission at ReportFraud.ftc.gov and to the Federal Communications Commission’s complaint center. You can also forward a scam text to 7726 (SPAM). Reporting helps the agencies spot patterns, even when the number on your screen was faked.
The Bottom Line
Area code 623 is the West Valley’s number: Glendale, Peoria, Surprise, Goodyear, Avondale, Buckeye, Sun City, and the towns between them, all in Maricopa County, all on Mountain Standard Time with no daylight saving. It was born in the three-way split of 602 on March 1, 1999, and since September 2023 it shares the whole Phoenix metro with 480 and 602 under one overlay. Dial all ten digits, every time. And when an unknown 623 number calls, let it ring — the area code tells you where the number lives, not who is using it.
Where is area code 623?
Area code 623 covers the West Valley of the Phoenix metro in Arizona — Glendale, Peoria, Surprise, Goodyear, Avondale, Buckeye, Sun City, and the smaller towns around them, all in Maricopa County.
What time zone is area code 623 in?
Mountain Standard Time (UTC-7) all year. Arizona does not observe daylight saving time, so 623 matches Pacific Time in summer and Mountain Time in winter.
Do I need to dial the area code for a 623 number?
Yes. Since August 12, 2023, ten-digit dialing is mandatory across the Phoenix metro — dial 623 plus the seven-digit number for every call, even across the street.
Is 623 a scam area code?
No, 623 is a normal geographic area code. But scammers can fake any caller ID, so the number alone proves nothing. Let unknown calls go to voicemail, hang up on pressure tactics, and report scams at ReportFraud.ftc.gov.
When was area code 623 created?
March 1, 1999, when the Arizona Corporation Commission split the original 602 area code three ways, creating 480 for the East Valley and 623 for the West Valley.
