Area code 605 – South Dakota
605 is one of the original area codes, in service across South Dakota since 1947. 745 of its 786 number blocks are allocated – about 95% full. Other CLEC / VoIP is the largest holder with 45.8% of blocks, ahead of Lumen / CenturyLink at 15.4%. Spam complaints are comparatively rare: 236 in the 33 days to 30 October 2026, 327th of the 422 codes with five or more complaints. Numbers are spread across 269 rate centers, which is typical of a mostly rural code.
- State
- South Dakota
- In service since
- 1947
- Time zone
- Central, Mountain
- Shares area with
- No overlay
Who holds 605 number blocks
Share of the 745 assigned NXX blocks (94.8% of the 786 possible), across 92 carriers. This is share of number blocks, not of subscribers.
- Other CLEC / VoIP49.1%
- Lumen15.4%
- Verizon13.7%
- AT&T11.5%
- T-Mobile3.2%
- Onvoy2.6%
- Bandwidth1.9%
- Consolidated0.5%
- Dish0.5%
- Telnyx0.4%
- Windstream0.3%
- Charter0.3%
- Frontier0.1%
- Comcast0.1%
- Twilio0.1%
- Vonage0.1%
Spam complaints naming 605
FTC Do Not Call complaints where the caller ID was a 605 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.
Rate centers in 605
NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 269.
Timeline
- 1947 605 assigned in the original North American Numbering Plan.
More about 605
Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.
Frequently asked about 605
What state is area code 605?
South Dakota.
Is a call from 605 a scam?
Not by itself. 605 drew 236 FTC complaints in the 33 days to 30 October 2026, 327th of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.
Which carrier owns 605 numbers?
Other CLEC / VoIP holds the largest share of assigned number blocks at 45.8%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.
Do I need to dial 10 digits in 605?
Yes – ten digits for local calls in 605, because it shares its area with another code.
Sources and verification
- NANPA – NPA Database (npa_report.csv), file date 11/01/2026, retrieved Nov 1, 2026
- NANPA – CO Code Assignment Records, All States (utilized), file updated 11/01/2026, retrieved Nov 1, 2026
- FTC – Do Not Call Reported Calls Data, 25 daily files 28 Sep – 30 Oct 2026, retrieved Nov 1, 2026
NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.