Area code
605
605 is a United States area code. Under the North American Numbering Plan it belongs to South Dakota, which has 1 area code in total.
Validate a number in 605
Paste a full number and the tool checks it against the numbering plan. It returns the standard formats, the line type the plan assigns and the area code region.
Digits with or without punctuation work. Numbers outside the US are read with the +country code.
Area code 605 at a glance
NANPA lists 744 central office codes (prefixes) in use in area code 605, held by 89 holders across 269 rate centers.
| Fact | Value |
|---|---|
| In service since | 1947-01-01 |
| Time zone | CM |
| Prefixes in use | 744 |
| Pooled prefixes | 365 (49%) |
| Rate centers | 269 |
| Companies holding prefixes | 89 |
| Assignment dates on file | 2001-01-16 to 2026-08-04 (256 prefixes) |
| ZIP codes in its places | 217 |
Rate centers in area code 605
| Rate center | Prefixes | Share |
|---|---|---|
| SIOUX FLS | 92 | 12% |
| RAPID CITY | 50 | 7% |
| ABERDEEN | 22 | 3% |
| SPEARFISH | 20 | 3% |
| WATERTOWN | 17 | 2% |
| HURON | 15 | 2% |
| PIERRE | 15 | 2% |
| YANKTON | 14 | 2% |
| 261 other rate centers | 499 | 67% |
Who holds the prefixes in 605
Qwest holds the most prefixes, 104 (14%). 49% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
| Holder | Prefixes | Share |
|---|---|---|
| Qwest | 104 | 14% |
| Verizon Wireless | 100 | 13% |
| New Cingular Wireless PCS | 81 | 11% |
| Midcontinent Communications. | 34 | 5% |
| Bluepeak | 32 | 4% |
| Venture Communications Cooperative | 30 | 4% |
| 83 other carriers | 363 | 49% |
A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company. Find which carrier a number is on, or browse the prefix holders.
History of area code 605
- 1947-01-01 Area code 605 went into service.
Area codes nearest to 605
Distance is measured between the centers of the ZIP code places each area code serves, so it is a rough guide.
ZIP codes in area code 605
217 ZIP codes fall in places that have a rate center in this area code.
| Place | ZIP codes |
|---|---|
| Rapid City, SD | 4 |
| Aberdeen, SD | 2 |
| Brookings, SD | 2 |
A ZIP code and an area code are unrelated systems. A ZIP code can sit in more than one area code, and an area code spans many ZIP codes.
Complaints on file for 605 numbers
1,809 FCC complaints are on file for 1,439 numbers in 605, most often filed as "Unwanted Calls". These are unverified consumer reports.
| Year of latest complaint | Numbers |
|---|---|
| 2023 | 82 |
| 2024 | 102 |
| 2025 | 69 |
South Dakota has one area code
605 is the only area code the table assigns to South Dakota, so every geographic number there starts with it.
Next to 605 in the numbering table
These are the codes just before and after 605 when all are sorted by number. They are neighbours on the list, not necessarily on the map.
What the area code does and does not tell you
A number that starts with 605 was first assigned in South Dakota. That is a fact about where the number began, and it is a useful hint when you check a form entry, for example a billing address in South Dakota next to a 605 phone number.
It does not show where the person is today. A number stays with its owner after a move or a change of provider (number portability), and mobile numbers travel with the handset. The area code also cannot tell you whether the line is active, who the carrier is, or whether the number is mobile or fixed: the plan shares those ranges. Read more about the area code, the numbering plan and line type.
Check numbers in bulk with the API
| Product | Credits | Docs |
|---|---|---|
| Phone Numbering-Plan Validation | 1 credit per valid number | API docs |
| Phone Intelligence (carrier and line status) | 1 credit per check (invalid numbers outside the US and Canada are free) | Product page |
Questions about area code 605
Where is area code 605?
NANPA assigns area code 605 to South Dakota, United States.
In which state does area code 605 sit?
South Dakota. 605 is one of 1 area code the NANPA table assigns to the state.
Which places does area code 605 cover?
The places with the most ZIP codes among the rate centers in 605 are Rapid City, SD, Aberdeen, SD and Brookings, SD. The rate center list on this page shows all of them.
Who owns area code 605?
NANPA assigns area codes. Within 605, Qwest holds the most prefixes, 104 prefixes or 14%.
Which time zone does 605 use?
The NANPA NPA report lists the time zone for 605 as CM.
What year did 605 enter service?
The NANPA NPA report gives an in-service date of 1947-01-01, so 605 has been in use since 1947.
Does area code 605 have an overlay?
The NANPA NPA report lists no other area code in an overlay with 605.
Which area codes are nearest to 605?
The area codes closest to 605, measured between the centers of the ZIP code places they serve, are 320 (about 221 miles), 701 (about 222 miles), 712 (about 233 miles), 308 (about 235 miles) and 402 (about 238 miles).
How many prefixes does area code 605 have?
NANPA's report dated 2026-10-17 lists 744 prefixes in service in 605, spread over 269 rate centers and 89 holders.
Are there complaints about 605 numbers?
The FCC data on file has 1,809 complaints for 1,439 numbers in 605. They are unverified consumer reports. A number with no complaints on file is not proven safe.
Area code assignments: North American Numbering Plan Administrator NPA report, file dated 10/17/2026, retrieved 2026-10-17. Source file. New codes are assigned several times a year. Prefixes, rate centers, holders, time zone, in-service date and overlays: NANPA central office code report dated 2026-10-17 and NPA report dated 2026-10-18. Complaints: FCC consumer complaints open data, fetched 2026-10-17. ZIP code places: Postal code places and coordinates: GeoNames (geonames.org), licensed CC BY 4.0.