The 406 area code covers Billings, Missoula and 213 more places in Montana.
Area code 406 is in Montana, on Mountain Time. In the 406 area, phone numbers are given out most in Yellowstone County, then Missoula and Gallatin counties. It has been in service since 1947.
- Where
- 8 counties in Montana, mostly Yellowstone County, Missoula County and Gallatin County
- Time zone
- Mountain Time
- In service since
- 1947, one of the original area codes
- Shares its area with
- No other area code
- Prefixes in use
- 754
- How to dial
- Local calls need all 10 digits: 406-555-0142.
Find out who called you from a 406 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (406) number is on today, use our free carrier lookup.
Works for US & Canada numbers. Enter a 10-digit number, e.g. (415) 555-0132.
Free & rate-limited. No signup required to try.
Billings holds 10% of the phone prefixes in area code 406.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 754 prefixes in use shows where 406 numbers are actually given out.
- Billings72 prefixes, 10%
- Missoula47 prefixes, 6%
- Helena38 prefixes, 5%
- Great Falls37 prefixes, 5%
- Bozeman32 prefixes, 4%
- Kalispell25 prefixes, 3%
- Butte17 prefixes, 2%
- Miles City10 prefixes, 1%
Also served: Sidney, Livingston, Lewistown and Hamilton and 203 smaller places.
Qwest (Lumen) holds the most phone number prefixes in area code 406: 132 of 754.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 754 prefixes in use in 406 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| Qwest (Lumen)Lumen's landline company | 132 | 18% |
| AT&T MobilityMobile network | 74 | 10% |
| Triangle Telephone Cooperative Association | 39 | 5% |
| Mid-Rivers Telephone Cooperative | 36 | 5% |
| Nemont Telephone Cooperative | 33 | 4% |
| 3 Rivers Telephone Cooperative | 30 | 4% |
| 51 other carriers | 410 | 54% |
70% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
406 has covered the same ground since 1947.
1947
406 is one of the original North American area codes.
A 406 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
These are the questions people ask most about area code 406.
Where is area code 406?
406 covers Billings, Missoula, Helena and Great Falls and 211 more places in Montana. In the 406 area, phone numbers are given out most in Yellowstone County, then Missoula and Gallatin counties.
What state is area code 406 in?
Montana. 406 is a Montana area code on Mountain Time.
What cities use area code 406?
The places holding the most 406 prefixes are Billings, Missoula, Helena, Great Falls, Bozeman, Kalispell, Butte and Miles City, out of 215 places in all. The count comes from NANPA's prefix assignments as of October 1, 2026.
Which phone company owns area code 406?
No single phone company owns 406. NANPA's records show Qwest (Lumen) holds the most 406 prefixes, 132 of 754, followed by AT&T Mobility and Triangle Telephone Cooperative Association. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 406 in?
406 is on Mountain Time.
When did area code 406 start?
406 is one of the original North American area codes, in service since 1947.
How do I dial a 406 number?
Local calls need all 10 digits: 406-555-0142.
Is 406 a toll-free number?
No. 406 is a regular area code for Billings and Missoula in Montana, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
Who called me from a 406 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 406 a scam?
406 is a real Montana area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.