What is the 605 Area Code? Time Zone and Location
- Area code 605 covers the entire state of South Dakota — it is the only area code that serves the area, making South Dakota one of only 11 states in the US with a single area code.
- There are currently no overlays, meaning 605 is the only area code for the geographic regions it serves — in all, it serves a population of 886,667 individuals across all 66 counties.
- Major cities covered include Sioux Falls, Rapid City, Aberdeen, Brookings, Pierre, Watertown, Mitchell, Yankton, Huron, Spearfish, Vermillion, Madison, Hot Springs, Lead, Sturgis, Belle Fourche, and Mobridge.
- The 605 area code spans two time zones — the majority of the state observes Central Time, while the western portion of the state, including Rapid City and the Black Hills, observes Mountain Time.
- Area code 605 was put into service on January 1, 1947, and was one of the original 86 area codes — it has served the entire state of South Dakota ever since without any splits.
- Area code 605 transitioned to mandatory 10-digit dialing by October 24, 2021, due to the nationwide designation of 988 as the National Suicide Prevention Lifeline.
- Current projections suggest South Dakota will require a second area code by late 2026, as 605 is nearing exhaustion.
Quick Facts
| Area Code | 605 |
|---|---|
| Country | United States |
| State / Region | South Dakota (entire state — all 66 counties) |
| Area Code Type | Geographic area code (no overlay — sole area code for the entire state) |
| Overlay Codes | None (second area code projected by late 2026) |
| Major Cities Covered | Sioux Falls, Rapid City, Aberdeen, Brookings, Pierre (state capital), Watertown, Mitchell, Yankton, Huron, Spearfish, Vermillion, Madison, Hot Springs, Lead, Sturgis, Belle Fourche, Mobridge, Winner, Chamberlain |
| Primary City Association | Sioux Falls, South Dakota (largest city) / Pierre, South Dakota (state capital) |
| Geographic Coverage | 273 cities across all 66 counties in South Dakota — from the Missouri River communities in central South Dakota to the Black Hills resort towns in the west and the agricultural heartland of the east |
| Time Zone | Dual time zone — Central Time (CT) for most of the state; Mountain Time (MT) for western counties, including Rapid City and the Black Hills |
| Central Time Offset | UTC −6 hours (standard) / UTC −5 hours (CDT) |
| Mountain Time Offset | UTC −7 hours (standard) / UTC −6 hours (MDT) |
| DST Period (2026 Example) | March → November |
| Introduced / Activation Date | January 1, 1947 — one of the original 86 area codes and the first and only area code ever assigned to South Dakota |
| Reason for Creation | One of the original 86 area codes established in 1947 under the NANP — the middle digit "0" confirms it was designed to cover the entire state, which it has done for nearly 80 years without a split |
| Dialing Requirement | 10-digit dialing has been mandatory since October 24, 2021, triggered by the national rollout of 988 as the Suicide Prevention Lifeline |
| Coverage Nature | Sole geographic area code — no overlay, though a second area code is projected for late 2026 as 605 approaches number exhaustion |
| Population Coverage | Serves a population of approximately 886,667 individuals across all 66 counties of South Dakota |
| Nearby / Related Area Codes | 402/531 (Omaha, NE), 406 (Montana), 507 (Rochester, MN), 612/763 (Minneapolis, MN), 701 (North Dakota), 307 (Wyoming), 308 (North Platte, NE) |
| Telecom System | North American Numbering Plan (NANP) |
| Major Carriers | South Dakota has approximately 1.2 million active phone numbers — cell phones make up the majority with 959,000 users, while traditional landlines have diminished to 113,000 connections, with internet phone services accounting for about 108,000 numbers |
| Example Phone Format | (605) XXX-XXXX |
| Usage Type | Mobile, landline, VoIP numbers |
| Business Use | The only area code for the entire state of South Dakota — universally recognized as the "South Dakota number" and essential for any business operating in the state |
| Number Availability | Currently uses 741 prefixes, assigned from 605-200-XXXX through 605-999-XXXX — nearing exhaustion, with a new area code projected for late 2026 |
| Area Code Status | Active — sole area code approaching exhaustion, with a new area code expected by late 2026 |
| Economic Profile | South Dakota does not have a general corporate income tax, which is why there are many financial companies headquartered in Sioux Falls — most notably the credit card divisions of major US banks like Citibank, Wells Fargo, and Capital One |
| Notable Distinction | Rapid City is nicknamed "Gateway to the Black Hills" and "City of Presidents," serving as the primary tourism gateway to Mount Rushmore, Crazy Horse Memorial, Badlands National Park, and Custer State Park, making the 605 area code synonymous with one of America's most iconic tourism landscapes |
Is the 605 Area Code a Scam?
| Spam Growth | Spam calls in South Dakota increased by 167.29% over the past year, with the highest volume recorded in September 2025, accounting for 21.68% of all calls, and the lowest in May 2026 at just 4.2% |
|---|---|
| Most Common Complaint Type | Prerecorded voice complaints make up 48.69% of all reported calls in South Dakota — the dominant statewide complaint type — followed by live voice at 32.35% and text message at 18.63% |
| Top Scam Categories | Auto warranty calls make up 13.07% of complaints — the single largest category — followed by credit card debt (6.86%), payday loans (6.21%), health insurance (5.56%), and mortgage loans (4.58%) |
| Top Reported Cities for Complaints | Sioux Falls leads with 27.5% of statewide complaints, followed by Rapid City (16.51%), Bonesteel (5.78%), Pierre (3.95%), and Aberdeen |
| Peak Complaint Period | March 2026 saw the highest volume of complaints for area code 605, with April 2026 showing an 80% decrease compared to March 2026 |
| Statewide Fraud Impact | In 2024, South Dakota residents reported 3,880 fraud cases resulting in total losses of $20,431,576, with a median loss of $400 per victim |
| Top Reported Fraud Types | Fake lawsuit threats and job scams are the most common reports for the 605 area code — the two dominant fraud patterns specifically flagged for South Dakota |
| SD BBB Warning | Officials from the South Dakota Better Business Bureau warn that if you're getting calls from telemarketers, there's a 3-to-1 chance they are actually criminals — scammers have specifically learned to use the 605 area code to make South Dakotans more likely to answer |
| Single-Code Statewide Vulnerability | South Dakota's entire state shares area code 605, so a number from Sioux Falls and one from Rapid City look identical — giving scammers maximum geographic flexibility to spoof any 605 number and appear local to any South Dakota community |
| Common Labels | Fake lawsuit caller, fake job recruiter, auto warranty robocaller, IRS arrest threat, payday loan harasser, voicemail hijacker |
| Spoofing Risk | Scammers have specifically found ways to use the 605 area code to make South Dakotans more likely to answer — a documented spoofing tactic that has been reported and warned about by South Dakota news outlets and the BBB |
| Typical Strategy | Automated callers pretend their headset is unplugged or that there's static to make the call sound like a real person rather than a robocall — using local 605 numbers to bypass caller ID suspicion in a state where any 605 call appears local |
| Signature Scam — Fake Federal Arrest Warrant | South Dakotans report receiving calls threatening that a federal warrant has been issued for their arrest — a tactic documented by Sioux Falls residents who say the calls are "relentless" and "they don't stop," using fear of law enforcement in rural communities where police authority carries significant weight |
| Signature Scam — Fake Lawsuit / Legal Threat | Callers threaten fake lawsuits against 605 residents — claiming civil complaints have been filed, referencing fake case numbers, and demanding immediate callback to avoid legal consequences — exploiting South Dakota's close-knit communities where legal threats carry particular social weight |
| Signature Scam — Fake Job Recruiter | Scammers pose as job recruiters offering attractive employment opportunities — collecting personal information, including SSNs, birthdates, and banking details, under the guise of pre-employment processing before the nonexistent job offer disappears along with the caller |
| Signature Scam — Voicemail Hijacking | South Dakotans are specifically warning each other about suspicious calls attempting to hijack voicemails — scammers gain access to voicemail accounts to intercept messages, collect personal information from voicemails, and use compromised accounts for further fraud |
| Reporting Authority | Report suspicious calls to the FTC at ReportFraud.ftc.gov, to the South Dakota AG's Consumer Protection Division at consumer.sd.gov, or call 1-800-300-1986; for South Dakota PUC telecom issues, contact Joseph Rezac at 605-773-5285 |
| Key Risk Indicator | Calls threatening federal arrest warrants, civil lawsuit claims with fake case numbers, job recruiters collecting personal information before any interview, or voicemail access alerts you didn't initiate |
| Safety Tip | If a number is on the Do Not Call list and still calls you — especially with a 605 area code number — it's very likely a scam, even if it's a South Dakota number. Real federal agencies do not call to threaten arrest; they send official mail. Any job that collects your SSN before an interview is a scam |
What Are the Business Benefits of the 605 Area Code?
| Local Presence | A 605 number is the definitive signal of South Dakota identity — as the only area code in the state since 1947, it is universally recognized by every South Dakota consumer, business, and government entity as a local number |
|---|---|
| Customer Trust Factor | A local 605 number dramatically increases answer rates vs. unknown out-of-state numbers in tight-knit South Dakota communities, where residents are significantly more likely to answer calls from the familiar 605 code |
| Statewide Coverage | One number covers all 66 counties of South Dakota — from the financial center of Sioux Falls in the east to the Black Hills tourism corridor of Rapid City in the west, and from the agricultural communities of the Missouri River Valley to the Native American reservation communities throughout the state |
| No Corporate Income Tax Advantage | South Dakota has no general corporate income tax — which is why major financial companies like Citibank, Wells Fargo, and Capital One have credit card operations in Sioux Falls — making a 605 number particularly valuable for financial services businesses drawn to South Dakota's tax-friendly environment |
| VoIP Compatibility | Easily available for SaaS platforms, call centers, and remote teams serving the South Dakota market |
| Scalability | Covers roughly 7.33 million unique phone numbers — though approaching exhaustion with a new area code projected for late 2026, meaning existing 605 numbers will retain their recognized status as South Dakota's original and primary code |
| Tourism Economy Access | Rapid City serves as the gateway to Mount Rushmore, Crazy Horse Memorial, Badlands National Park, and Custer State Park. South Dakota draws millions of visitors annually, making a 605 area code essential for any business serving the state's enormous tourism economy |
| Marketing Use | Ideal for local SEO, digital ads, and customer outreach across Sioux Falls, Rapid City, Aberdeen, Brookings, Pierre, Watertown, Mitchell, Yankton, Huron, Spearfish, and surrounding communities |
| Startup Friendly | South Dakota's zero corporate income tax and zero personal income tax make it one of the most business-friendly states in the country — a 605 number combined with South Dakota's favorable tax structure is particularly attractive for financial services, banking, and technology startups |
| Call Routing Flexibility | Can route calls globally while appearing local to South Dakota customers — particularly valuable for financial services companies managing national credit card and banking operations from Sioux Falls |
| Top Industries | Financial services and credit card processing (Citibank, Wells Fargo, Capital One Sioux Falls operations), healthcare (Sanford Health, Avera Health), agriculture (corn, soybeans, wheat, cattle, hogs), tourism (Mount Rushmore, Badlands, Sturgis Motorcycle Rally), higher education (South Dakota State University, University of South Dakota, South Dakota School of Mines), government (state capital Pierre), and energy (wind power — South Dakota ranks among the top states for wind energy) benefit most from a local 605 presence |
| Use Case Examples | AI receptionist, financial services and credit card operations lines, healthcare practices and hospital networks, agricultural equipment and supply services, tourism and Black Hills visitor services, university admissions and affiliated research services, state government agency lines, wind energy development support, and local retail and hospitality businesses |
