Area codes · +1
Area code 307
Area code 307 is centred on Cheyenne, Wyoming. We hold 2,816 allocated blocks for it across 92 rate centres, split 38% mobile, 43% landline and 19% VoIP.
The towns inside area code 307
Area code 307 is not a city code. It covers 92 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 307 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.
307 is the only area code whose numbers sit mainly in Wyoming. Every Wyoming number therefore starts 307 unless it was issued in a border rate centre billed to a neighbouring code.
Where 307 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why Rock Spg is shortened. Names are reproduced as recorded rather than expanded — the abbreviation is the key the block data is filed under.
| Rate centre | Blocks | Share of 307 |
|---|---|---|
| Cheyenne | 397 | 14% |
| Casper | 249 | 9% |
| Jackson | 124 | 4% |
| Sheridan | 119 | 4% |
| Cody | 111 | 4% |
| Gillette | 110 | 4% |
| Laramie | 102 | 4% |
| Rock Spg | 99 | 4% |
| Riverton | 89 | 3% |
| Douglas | 77 | 3% |
| Powell | 75 | 3% |
| Buffalo | 63 | 2% |
| Lander | 61 | 2% |
| Evanston | 58 | 2% |
| Afton | 56 | 2% |
| Torrington | 52 | 2% |
| Rawlins | 51 | 2% |
| Wheatland | 51 | 2% |
| Greenriver | 49 | 2% |
| Lusk | 46 | 2% |
| Kemmerer | 42 | 1% |
| La Grange | 40 | 1% |
| Pinedale | 38 | 1% |
| Wright | 33 | 1% |
68 further rate centres in 307 hold fewer blocks than these.
Carriers holding the most 307 blocks
Onvoy620 blocks
Verizon Wireless360 blocks
AT&T Wireless300 blocks
Qwest Corporation257 blocks
Bandwidth184 blocks
T-Mobile Usa, Inc.112 blocks
The largest holder, Onvoy, has 22% of the code.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 307 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 307 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 307?
Area code 307 is centred on Cheyenne, Wyoming and spans 92 rate centres, so it covers a region rather than a town.
Is a 307 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 307 the split runs 38% mobile, 43% landline and 19% VoIP, so landline is the most likely single answer.
Which carriers hold 307 numbers?
The largest holders are Onvoy, Verizon Wireless, AT&T Wireless. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 307 numbers are there?
The code holds 2,816 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 307 covers on the order of 2,816,000 possible numbers — most of which have never been issued to anyone.