Area codes · +1
Area code 605
Area code 605 is centred on Sioux Falls, South Dakota. We hold 3,701 allocated blocks for it across 269 rate centres, split 44% mobile, 43% landline and 13% VoIP.
The towns inside area code 605
Area code 605 is not a city code. It covers 269 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 605 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.
605 is the only area code whose numbers sit mainly in South Dakota. Every South Dakota number therefore starts 605 unless it was issued in a border rate centre billed to a neighbouring code.
Where 605 numbers are concentrated
NANPA truncates rate-centre names to ten characters and drops the spaces, which is why Sioux Fls and Lk Preston are 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 605 |
|---|---|---|
| Sioux Fls | 607 | 16% |
| Rapid City | 331 | 9% |
| Aberdeen | 168 | 5% |
| Spearfish | 109 | 3% |
| Pierre | 91 | 2% |
| Harisbgtea | 90 | 2% |
| Watertown | 90 | 2% |
| Huron | 88 | 2% |
| Redfield | 84 | 2% |
| Sturgis | 79 | 2% |
| Vermillion | 77 | 2% |
| Mitchell | 76 | 2% |
| Yankton | 70 | 2% |
| Flandreau | 68 | 2% |
| Madison | 68 | 2% |
| Brookings | 54 | 1% |
| Milbank | 53 | 1% |
| Belleforch | 50 | 1% |
| Chamberlan | 41 | 1% |
| Miller | 39 | 1% |
| Hill City | 37 | 1% |
| Lk Preston | 37 | 1% |
| Martin | 37 | 1% |
| Arlington | 35 | 1% |
245 further rate centres in 605 hold fewer blocks than these.
Carriers holding the most 605 blocks
Verizon Wireless768 blocks
Onvoy512 blocks
Qwest Corporation411 blocks
AT&T Wireless389 blocks
Bandwidth167 blocks
James Valley Cooperative Telephone Company130 blocks
The largest holder, Verizon Wireless, has 21% of the code.
These are original allocations. A number keeps its digits and its block when its subscriber moves network, so a ported 605 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 605 number, or run a whole list through the free cleaner — neither uploads anything.
Common questions
Where is area code 605?
Area code 605 is centred on Sioux Falls, South Dakota and spans 269 rate centres, so it covers a region rather than a town.
Is a 605 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 605 the split runs 44% mobile, 43% landline and 13% VoIP, so mobile is the most likely single answer.
Which carriers hold 605 numbers?
The largest holders are Verizon Wireless, Onvoy, Qwest Corporation. That is the carrier the block was allocated to, which is not necessarily the network a given number sits on today.
How many 605 numbers are there?
The code holds 3,701 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 605 covers on the order of 3,701,000 possible numbers — most of which have never been issued to anyone.