The 605 area code covers Sioux Falls, Rapid City and 223 more places in South Dakota.
Area code 605 is in South Dakota, on Central Time and Mountain Time. In the 605 area, phone numbers are given out most in Minnehaha County, then Pennington and Brown counties. It has been in service since 1947.
- Where
- 8 counties in South Dakota, mostly Minnehaha County, Pennington County and Brown County
- Time zone
- Central Time and Mountain Time
- In service since
- 1947, one of the original area codes
- Shares its area with
- No other area code
- Prefixes in use
- 745
- How to dial
- Local calls need all 10 digits: 605-555-0142.
Find out who called you from a 605 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (605) number is on today, use our free carrier lookup.
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Sioux Falls holds 12% of the phone prefixes in area code 605.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 745 prefixes in use shows where 605 numbers are actually given out.
- Sioux Falls92 prefixes, 12%
- Rapid City50 prefixes, 7%
- Aberdeen22 prefixes, 3%
- Spearfish20 prefixes, 3%
- Watertown17 prefixes, 2%
- Pierre15 prefixes, 2%
- Huron15 prefixes, 2%
- Yankton14 prefixes, 2%
Also served: Mitchell, Brookings, Vermillion and North Sioux City and 213 smaller places.
Qwest (Lumen) holds the most phone number prefixes in area code 605: 104 of 745.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 745 prefixes in use in 605 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| Qwest (Lumen)Lumen's landline company | 104 | 14% |
| AT&T MobilityMobile network | 81 | 11% |
| Midcontinent Communications. | 34 | 5% |
| Bluepeak | 33 | 4% |
| Venture Communications Cooperative | 30 | 4% |
| Interstate Telecom Cooperative | 28 | 4% |
| 80 other carriers | 435 | 58% |
49% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
605 has covered the same ground since 1947.
1947
605 is one of the original North American area codes.
A 605 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 605 are 701, 308 and 402.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
These are the questions people ask most about area code 605.
Where is area code 605?
605 covers Sioux Falls, Rapid City, Aberdeen and Spearfish and 221 more places in South Dakota. In the 605 area, phone numbers are given out most in Minnehaha County, then Pennington and Brown counties.
What state is area code 605 in?
South Dakota. 605 is a South Dakota area code on Central Time and Mountain Time.
What cities use area code 605?
The places holding the most 605 prefixes are Sioux Falls, Rapid City, Aberdeen, Spearfish, Watertown, Pierre, Huron and Yankton, out of 225 places in all. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 605?
No single phone company owns 605. NANPA's records show Qwest (Lumen) holds the most 605 prefixes, 104 of 745, followed by AT&T Mobility and Midcontinent Communications.. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 605 in?
605 is on Central Time and Mountain Time.
When did area code 605 start?
605 is one of the original North American area codes, in service since 1947.
How do I dial a 605 number?
Local calls need all 10 digits: 605-555-0142.
Is 605 a toll-free number?
No. 605 is a regular area code for Sioux Falls and Rapid City in South Dakota, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 605?
The closest are 701 (Fargo, North Dakota), 308 (Grand Island, Nebraska) and 402/531 (Omaha, Nebraska), measured between the centres of each area.
Who called me from a 605 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 605 a scam?
605 is a real South Dakota area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.