South Dakota area codes
One area code — 605 — covers all of South Dakota. The state's numbering history begins in 1947 with 605. Most recent addition: 605, in service since 1947.
Coverage runs through 605 (Sioux Falls); prefix counts in the table approximate each code's numbering footprint.
Clocks differ across the state's codes (Central, Mountain) — worth checking before a callback.
A statewide single code is getting rare in the NANP — most states have long since added overlays. 605 still covers everything from Sioux Falls to Spearfish on one code.
605 has served Sioux Falls since 1947, carries 742 active prefixes across 269 rate centers, split among 92 carriers. 363 of its prefixes are pooled — shared between carriers in thousands-number blocks. It is the only area code serving South Dakota. NANPA projects its capacity to last until 3Q 2034. Local dialing is ten digits.
Toll-free callers are a separate story: 800-family numbers carry no South Dakota geography at all, so an 833 or 877 number is never "from" the state — it belongs to whichever business rents it, anywhere in the NANP.
A number in any of these codes was issued in South Dakota, but portability means its owner may be anywhere today — the codes locate numbers, not people. To dig further, open a code's prefix or cities pages.
| Code | Major area | In service | Overlay complex | Prefixes |
|---|---|---|---|---|
| 605 | Sioux Falls | 1947 | — | 742 |
FAQ
How many area codes does South Dakota have?
1 geographic area code is currently in service: 605.
Will South Dakota get a new area code soon?
Not soon. The earliest exhaust forecast in the state is 605 at 3Q 2034, so current codes have ample capacity.
Which time zone are South Dakota numbers in?
South Dakota codes span Central and Mountain time; check each code's page for its zone.