Spam calls from area code 605? Here's how to stop them.
Area code 605 covers all of South Dakota. The spammers faking it could be anywhere in the state — or nowhere near it. Here's the fix.
If your phone keeps lighting up with area code 605 calls, here's the truth: it's almost certainly not someone in Sioux Falls, SD. It's a robocaller spoofing a statewide South Dakota number so the call looks local and you pick up. You hang up, they dial the next 605 number. You're one row in a spreadsheet.
Don't block 605 — screen it. Real calls come from 605 too. Known callers should ring through; unknown 605 numbers should hit a wall first.
What 605 actually is
Across a sample of 18,440 recent FTC reports (through 2026-07-23), consumers logged 42 complaints about calls that displayed a 605 number. Because caller ID is spoofed, almost none actually originated in Sioux Falls — the number is a costume, and this is how often it gets worn against people who share it.
605 is an original-era code. Its middle digit (0) dates it to the 1947–1995 numbering plan, when the middle digit could only be 0 or 1. Codes this old cover long-settled, densely-dialed territory — which is exactly why spoofers love wearing them: a 605 number reads as established and trustworthy.
605 is the only area code in all of South Dakota. So a spoofed 605 call isn't just faking your town — it's faking your entire state. When you see 605, 'local' could mean the next street or the far corner of South Dakota, and the actual dialer is usually neither.
One tell the spoof can't hide: time. Numbers on 605 belong to the Central time zone. A "local" 605 call that rings at 3 a.m. almost always originated in a boiler room several zones away, dialing your daytime from their own.
Why 605 keeps calling you
Spoofing engines pull the first six digits of your number and dial matching 605 numbers — the “neighbor” trick. A call sharing your area code and prefix feels safe, so answer rates jump. That's the whole scam: familiarity. Read the mechanics in neighbor spoofing, and why you got picked in why me?
Shut down 605 spam calls — free
- Silence unknown callers. The single biggest win. Set it up on iPhone or Android in 30 seconds.
- Turn on your carrier's filter. Free on AT&T, Verizon, and T-Mobile.
- Register on the Do Not Call list. Won't stop scammers, but it makes the legal ones back off and gives you standing to report.
- Weaponize the rest. The calls that still get through? Hand them to the Crew — an AI answers in character and wastes the scammer's time on a call they thought was a real mark.
Why am I getting spam calls from area code 605?
Because auto-dialers spoof it. They fake a 605 (Sioux Falls, SD) number so the call looks local and you answer. The caller is almost never actually in Sioux Falls — the number is a mask, and an established code like 605 picks it precisely because it looks close to you. See neighbor spoofing.
Could a real 605 call be legitimate?
Yes — and here it matters more than usual. 605 is the only area code in South Dakota, so real businesses and neighbors across the whole state carry it. Blanket-blocking 605 would cut off the entire state. Screen it instead: known contacts ring through, unknown 605 numbers hit a wall first.
How do I stop 605 spam calls for free?
Turn on Silence Unknown Callers (iPhone / Android), register on the Do Not Call list, and switch on your carrier's free spam filter. For the ones that still slip through, hand them to the Crew — the AI answers in character (in English, Spanish, Russian, or Mandarin) and wastes the scammer's time instead of yours.