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Area code Verified Nov 1, 2026 · Source: NANPA

Area code 406 – Montana

406 is one of the original area codes, in service across Montana since 1947. 754 of its 786 number blocks are allocated – about 96% full. Other CLEC / VoIP is the largest holder with 35.9% of blocks, ahead of Lumen / CenturyLink at 24.5%. FTC complaints naming a 406 caller ID totalled 647 in the 33 days to 30 October 2026 (161st of 422 ranked codes). Numbers are spread across 260 rate centers, which is typical of a mostly rural code.

State
Montana
In service since
1947
Time zone
Mountain
Shares area with
No overlay

Who holds 406 number blocks

Share of the 754 assigned NXX blocks (95.9% of the 786 possible), across 63 carriers. This is share of number blocks, not of subscribers.

  • Other CLEC / VoIP34.6%
  • Lumen24.5%
  • Verizon16.3%
  • AT&T10.7%
  • Onvoy5.7%
  • Charter3.7%
  • T-Mobile0.9%
  • Bandwidth0.5%
  • Ziply Fiber0.5%
  • Allstream0.5%
  • Telnyx0.5%
  • TDS0.3%
  • Comcast0.3%
  • Dish0.3%
  • Vonage0.3%
  • Twilio0.3%

Spam complaints naming 406

FTC Do Not Call complaints where the caller ID was a 406 number, 28 Sep – 30 Oct 2026 (33 days). Caller IDs on spam calls are frequently spoofed, so these are complaints about the code, not calls proven to originate in it.

647 complaints in 33 days
#161 of 422 ranked codes

Rate centers in 406

NANPA allocates number blocks to rate centers and records their names abbreviated to ten characters, so these are NANPA's codes rather than place names – CHAMPAURBN is Champaign-Urbana, NWYRCYZN01 is a New York City zone. We show them unchanged instead of guessing at the full names. Showing the largest 5 of 260.

BILLINGS72
MISSOULA47
HELENA38
GREATFALLS37
BOZEMAN32

Timeline

  1. 1947 406 assigned in the original North American Numbering Plan.

More about 406

Separate pages for the questions that need their own answer: what time it is there, what the complaint data says, who holds the number blocks, and how the code compares with the one it shares its area with.

All prefixes Every one of the 754 assigned NXX blocks, with the holder of each Local time Zone, UTC offset, clock changes and a live clock Spam complaints How often the code appears in FTC complaints, and what to do Carriers Who holds the number blocks, and why that is not who serves them

Frequently asked about 406

What state is area code 406?

Montana.

Is a call from 406 a scam?

Not by itself. 406 drew 647 FTC complaints in the 33 days to 30 October 2026, 161st of 422 ranked codes – mid-pack or lower. Spam callers spoof caller IDs, so the only useful check is the full number.

Which carrier owns 406 numbers?

Other CLEC / VoIP holds the largest share of assigned number blocks at 35.9%. The rest is spread across 3 other carriers. This is share of number blocks, not of subscribers – people keep their numbers when they switch carriers.

Do I need to dial 10 digits in 406?

Yes – ten digits for local calls in 406, because it shares its area with another code.

Sources and verification

NANPA dialing note for this code: “10D”. Reviewed by the data desk. Spotted an error? Request a correction.