Area code 520: Arizona
What is area code 520?
Area code 520 is a US state area code for Arizona, on Mountain Standard Time. It has 694 prefixes in service across 37 rate centers, the largest being Tucson, Sierra Vista and Casa Grande. NANPA lists no overlay code for it. Local calls there take 10 digits. The code never shows a line is in service.
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See the phone add-onArea code 520 facts
| Location | Arizona, United States |
|---|---|
| Time zone | Mountain Standard Time |
| Overlays | None |
| Split from | 602 |
| In service since | March 19, 1995 |
| Local calls | 10 digits; toll calls 1 + 10 digits |
| Carrier | Not shown. An area code is where a number was issued; numbers port between carriers. Check line type |
In short: 520 is Arizona (Mountain Standard Time). Format checks here are free and run in your browser; the current carrier and line type need a live lookup. Bulk phone number validator · Pro + Phone plan
Local time in area code 520
America/Phoenix
Prefixes in service
694 of 792 possible
37 rate centers
Which cities and towns use area code 520?
NANPA records each prefix against a rate center, the local billing area a number belongs to, usually named after its main town. These are the 520 rate centers with the most prefixes in service. 25 smaller ones aren't listed.
| Rate center | Prefixes |
|---|---|
| Tucson | 399 |
| Sierra Vista | 70 |
| Casa Grande | 67 |
| Nogales | 31 |
| Willcox | 18 |
| Benson | 12 |
| Hayden | 9 |
| Bisbee | 9 |
| Douglas | 9 |
| San Manuel | 8 |
| Tombstone | 7 |
| Whitlow | 7 |
Source: NANPA central office code assignments, file dated 10/17/2026. Each prefix holds up to 10,000 numbers.
How do I dial a 520 number?
NANPA's dialling plan for 520: local calls inside the code take 10 digits, toll calls 1 + 10 digits. From another area code, dial 1 first. From abroad, use +1. The examples use 555-0147, from a range reserved for fictional numbers.
| Local call inside 520 | 520-555-0147 |
|---|---|
| From another US or Canadian area code | 1-520-555-0147 |
| From outside North America | +1 520 555 0147 |
| E.164, for CRMs and SMS tools | +15205550147 |
When did area code 520 start?
Area code 520 went into service on March 19, 1995, split from 602. It has no overlay, so every number in its area still starts with it.
Tools for 520 numbers
- Bulk phone number validator
Format, country and number type for every number in a CSV, with E.164 output.
- Area code lookup
Look up any code or a whole list of numbers, or find the codes for a state or city.
- Area code time zone
Local time for a list of numbers, with a callable-now flag.
- NPA-NXX lookup
Rate center and state for one prefix, a level below the area code.
- TCPA calling hours checker
Whether it's inside the federal 8 a.m. to 9 p.m. calling window there now.
Next step
A 520 number tells you where it was issued, not what it is now.
Mobiles, landlines and VoIP lines share area codes, and numbers move between carriers. A live line-type and carrier lookup on every number in your list says which is which, and that decides which calling and texting rules apply. It's in the phone add-on.
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Area code 520 questions
- What state is area code 520?
- Area code 520 is in Arizona, United States. Its largest rate centers by number of prefixes are Tucson, Sierra Vista, Casa Grande, Nogales and Willcox.
- What time zone is area code 520 in?
- Mountain Standard Time.
- Does area code 520 have an overlay?
- Not as of NANPA's file dated 10/16/2026. Every number in its area uses 520.
- When did area code 520 start?
- Area code 520 went into service on March 19, 1995, split from 602.
- Is a 520 number a cell phone or a landline?
- The area code can't tell you. In the US and Canada mobiles, landlines and VoIP lines share area codes and prefixes, and numbers move between carriers and line types. Only a live line-type lookup answers it for one number.
- How many phone numbers does area code 520 have?
- 694 of its 792 possible prefixes are in service, and each prefix holds up to 10,000 numbers. That counts prefixes assigned to carriers, not numbers in use.
- Does a valid format mean a 520 number is in service?
- No. A format check only says the digits fit the North American Numbering Plan and that 520 is an assigned code. It cannot tell whether the number is connected, who answers it or which carrier serves it today, because numbers are reassigned and ported. A live carrier lookup reports the current carrier and line type, but even that is not proof someone answers.
- Can I check a list of 520 numbers for free?
- Yes. Paste them in the list tab above or upload a CSV to the bulk phone number validator: format, E.164, country and the numbering-plan line type are free for every row, with no account. Live carrier and line-type lookups come with Pro + Phone at $49.99/mo (5,000 a month).
Other area codes in Arizona
All Arizona area codes on the area code index.
Sources
Location, overlays, in-service date and dialling plan: NANPA NPA database, file dated 10/16/2026. Prefixes and rate centers: NANPA central office code assignments, 10/17/2026. Time zones mapped to the IANA time zone database. By the SimpleVerifier Team; how we build these pages.