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Area code 520

Area code 520 serves Arizona, including Tucson, Sierra Vista and Casa Grande (Mountain time). It has been in service since March 19, 1995.

Numbers starting with 520 drew 4,218 reports to the FTC from Aug 14, 2026 to Nov 11, 2026 and 1,249 complaints to the FCC since November 2023. The number on your screen can be faked, so a 520 number proves nothing about where a call came from.

Location
ArizonaPhoenix-Mesa-Chandler, AZ Metropolitan Statistical Area and Tucson, AZ Metropolitan Statistical Area
Time zone
Mountain
In service since
March 19, 1995Created from 602
Overlay
None: the only code for its area
Local calls
Dial 10 digitsArea code needed, even next door
Exchanges in use
699 of 792held by 52 carriers
Projected to run out
2Q 2033NANPA forecast 2026.2

Complaints about 520 numbers

Reports where the number on the consumer's caller ID (or, for the FCC, the number the caller asked them to call back) starts with 520. These are counts of what people reported; the agencies do not verify them.

FTC reports, Aug 14, 2026 to Nov 11, 2026

4,218

FCC complaints since November 2023

1,249

Different 520 numbers reported

4,886

FCC complaints naming a 520 number, by month

November 2023 to October 2026. Source: FCC Consumer Complaints Data.

Show as a table
MonthComplaints
November 202321
December 202312
January 202434
February 202430
March 202418
April 202429
May 202436
June 202427
July 202444
August 202436
September 202448
October 202459
November 202453
December 202431
January 202540
February 202537
March 202527
April 202518
May 202529
June 202529
July 202533
August 202526
September 202524
October 20252
November 20259
December 202529
January 202624
February 202631
March 202623
April 202645
May 202624
June 202649
July 202641
August 202669
September 202655
October 202673

What people said 520 calls were about

Subjects picked in FTC reports, August 14, 2026 to November 11, 2026. 3,051 of 4,218 reports were robocalls.

Show as a table
SubjectReports
Other1,782
Reducing your debt (credit cards, mortgage, student loans)1,024
Calls pretending to be government, businesses, or family and friends386
Medical and prescriptions352
Dropped call or no message214
Home improvement and cleaning45

Most reported 520 numbers

Numbers with at least five reports from three or more places in the last twelve months. Many of them are likely spoofed.

Places served by 520

NANPA lists 37 rate centers for 520. A rate center is the town or district a block of numbers is tied to for billing; sorted here by how many exchanges each holds.
  • Tucson400
  • Sierra Vista70
  • Casa Grande67
  • Nogales32
  • Willcox18
  • Benson12
  • Douglas10
  • Hayden10
  • Bisbee9
  • San Manuel9
  • Superior7
  • Tombstone7
  • Whitlow7
  • Sacaton4
  • Sasabe3
  • Sells3
  • Ajo2
  • Blackwater2
  • Casa Blanca2
  • Cascabel2
  • Komatke2
  • Lone Butte2
  • Maricopa Village2
  • Portal2
Show all 37 rate centers

Santa Rosa, Silver Bell, Bowie, Elfrida, Flagstaff, Pearce, Prescott, San Simon, Sedona, Stotonic, Sunizona, West San Simon, Yuma.

Phone companies holding 520 exchanges

Each exchange (the three digits after the area code) is assigned to one carrier. 70% of these exchanges are pooled: their numbers are handed out in blocks of 1,000 to other carriers, so the holder below is not always the company serving a given number.

Exchanges held, top 8 of 52 carriers

NANPA central office code assignments, file of November 11, 2026.

Show as a table
Carrier (legal name)Exchanges
Qwest Corporation200
Cellco Partnership dba Verizon Wireless - AZ104
T-Mobile USA, Inc.84
New Cingular Wireless PCS, LLC53
Onvoy, LLC - AZ47
Mcimetro Access Transmission Services LLC - AZ24
Bandwidth.com CLEC, LLC - AZ17
Level 3 Communications, LLC - AZ17

When today's 520 exchanges were assigned

Exchanges still assigned, by year of assignment. Exchanges returned since are not counted.

Show as a table
YearExchanges
200119
200212
20034
20045
20054
20064
200712
20087
20099
20105
20118
201216
20139
201420
201517
201610
20177
20184
201912
202035
202135
202228
202328
202422
202511
20268

Check a 520 number

A check shows the carrier and rate center of the number's exchange and every FTC and FCC report about that exact number. Why the number on screen can be fake.

Other area codes in Arizona

NANPA area code database and central office code file of November 11, 2026; FCC complaints November 1, 2023 to November 11, 2026; FTC reports August 14, 2026 to November 11, 2026. How the data is used.

Official sources (7)Show