Area codes · +1
Area code 520
Area code 520 is centred on Tucson, Arizona. We hold 5,373 allocated blocks for it across 37 rate centres, split 45% mobile, 42% landline and 13% VoIP.
The towns inside area code 520
Area code 520 is not a city code. It covers 37 separate rate centres — billing areas, each its own local calling zone. The largest of them are named in the table below.
That matters twice over. A call between two 520 numbers is not necessarily a local call, because they can sit in different rate centres. And a code this wide narrows a subscriber to a region rather than a town.
Arizona is split across 5 area codes — 480, 520, 602, 928, 623. By allocated blocks 520 is the second largest of them, holding 23% of the Arizona total.
Where 520 numbers are concentrated
Rate-centre names are reproduced as NANPA records them. The agency truncates them to ten characters, so longer names appear shortened elsewhere on this site.
| Rate centre | Blocks | Share of 520 |
|---|---|---|
| Tucson | 2,859 | 53% |
| Casagrande | 608 | 11% |
| Sierravist | 608 | 11% |
| Nogales | 288 | 5% |
| Willcox | 160 | 3% |
| Benson | 120 | 2% |
| Hayden | 96 | 2% |
| Bisbee | 93 | 2% |
| Douglas | 89 | 2% |
| San Manuel | 87 | 2% |
| Whitlow | 73 | 1% |
| Superior | 72 | 1% |
| Tombstone | 71 | 1% |
| Sacaton | 27 | 1% |
| Sasabe | 19 | 0% |
| Sells | 13 | 0% |
| Ajo | 8 | 0% |
| Casablanca | 5 | 0% |
| Lone Butte | 5 | 0% |
| Prescott | 5 | 0% |
| Silverbell | 5 | 0% |
| Cascabel | 4 | 0% |
| Komatke | 4 | 0% |
| Marcopavlg | 4 | 0% |
13 further rate centres in 520 hold fewer blocks than these.
Carriers holding the most 520 blocks
Verizon Wireless820 blocks
Qwest Corporation686 blocks
Onvoy649 blocks
AT&T Wireless488 blocks
T-Mobile Usa, Inc.479 blocks
T-Mobile USA, Inc.432 blocks
The largest holder, Verizon Wireless, has 15% of the code.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 520 number still reports the carrier it started with. Closing that gap needs a live query against the routing database. How line type is derived.
Check a single 520 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 520?
Area code 520 is centred on Tucson, Arizona and spans 37 rate centres, so it covers a region rather than a town.
Is a 520 number a mobile or a landline?
It can be either, and the digits do not say which. North American mobile and landline numbers share the same ranges, so the answer comes from the carrier holding the block. In 520 the split runs 45% mobile, 42% landline and 13% VoIP, so mobile is the most likely single answer.
Which carriers hold 520 numbers?
The largest holders are Verizon Wireless, Qwest Corporation, Onvoy. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 520 numbers are there?
The code holds 5,373 allocated blocks in our copy of the numbering plan. A block is 1,000 or 10,000 consecutive numbers depending on how deeply it has been pooled, so 520 covers on the order of 5,373,000 possible numbers — most of which have never been issued to anyone.