406 area code
Area code 406 is in Montana. It covers Billings, Missoula, Great Falls and 537 other places: 386 ZIP codes in Yellowstone, Gallatin, Missoula and 53 other counties. Local time there is , Mountain Time. In service since 1947, with no overlay.
Who calls from a 406 number
NANPA records the carrier each block of 406 numbers is assigned to. Of the 6.5 million 406 numbers assigned, 41% are with local phone companies (Qwest (CenturyLink), Triangle Tel. Coop. Assn. and 3 Rivers Tel. Coop.); 31% with cable, internet-calling, business and other carriers (Onvoy); 28% with mobile carriers (Verizon Wireless and AT&T Mobility).
That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.
| Carrier | Kind | Share |
|---|---|---|
| Verizon Wireless | Mobile | 17% |
| Onvoy | Cable, VoIP, other | 15% |
| Qwest (CenturyLink) | Landline | 14% |
| AT&T Mobility | Mobile | 7% |
| Triangle Tel. Coop. Assn. | Landline | 5% |
| 3 Rivers Tel. Coop. | Landline | 4% |
An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.
Places in area code 406
The 222 places with a telephone rate centre of their own using 406, largest first. Each links to its ZIP codes.
Nearby places using 406
These places have no rate centre of their own in NANPA's records; the nearest one uses 406. Near an area-code boundary that can be wrong for part of a town.
- Butte-Silver Bow
- Evergreen
- Anaconda-Deer Lodge County
- Helena Valley Southeast
- Helena Valley West Central
- Lockwood
- Four Corners
- Orchard Homes
- Helena Valley Northwest
- Helena Valley Northeast
- Lolo
- Malmstrom Afb
- North Browning
- Montana City
- Crow Agency
- East Missoula
- King Arthur Park
- Bonner
- Clancy
- East Helena
- Wheatland
- Bonner-West Riverside
- South Browning
- Helena West Side
- Corvallis
- Fort Belknap Agency
- Sun Prairie
- Churchill
- Pray
- Wye
- Rocky Boy West
- Vaughn
- White Haven
- Ponderosa Pines
- Florence
- Ulm
- Havre North
- Helena Flats
- Woods Bay
- Pinesdale
- Pioneer Junction
- Black Eagle
- Park City
- Spokane Creek
- Walkerville
- Muddy
- Trego
- Batavia
- Carlton
- South Hills
- Riverbend
- The Silos
- Turah
- Jefferson City
- Lindisfarne
- Heart Butte
- Pryor
- West Kootenai
- Lewistown Heights
- Evaro
ZIP codes in area code 406
386 ZIP codes in 342 towns, by the town each is mailed to, largest first. Each links to its own page.
Where 406 numbers are issued
NANPA's rate centres with the most 406 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.
| Rate centre | Place | Prefixes |
|---|---|---|
BILLINGS | Billings | 72 |
MISSOULA | Missoula | 47 |
HELENA | Helena | 38 |
GREATFALLS | Great Falls | 37 |
BOZEMAN | Bozeman | 32 |
KALISPELL | Kalispell | 25 |
Counties
The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.
- Yellowstone County (22)
- Gallatin County (12)
- Missoula County (16)
- Flathead County (16)
- Cascade County (18)
- Lewis and Clark County (15)
- Ravalli County (10)
- Lake County (12)
- Silver Bow County (7)
- Lincoln County (7)
- Park County (9)
- Hill County (7)
- Glacier County (4)
- Jefferson County (6)
- Sanders County (9)
- Custer County (3)
- Big Horn County (11)
- Richland County (5)
- Fergus County (8)
- Roosevelt County (6)
- Carbon County (10)
- Deer Lodge County (3)
- Stillwater County (8)
- Madison County (11)
- Beaverhead County (7)
- Dawson County (4)
- Rosebud County (9)
- Valley County (10)
- Powell County (7)
- Blaine County (6)
- Teton County (6)
- Pondera County (5)
- Mineral County (6)
- Granite County (4)
- Broadwater County (4)
- Chouteau County (7)
- Musselshell County (3)
- Toole County (7)
- Phillips County (6)
- Sheridan County (10)
- Sweet Grass County (3)
- Fallon County (3)
- Powder River County (3)
- Liberty County (5)
- Judith Basin County (6)
- Wheatland County (4)
- Meagher County (3)
- Daniels County (4)
- McCone County (4)
- Prairie County (3)
- Wibaux County (1)
- Carter County (3)
- Treasure County (3)
- Golden Valley County (2)
- Garfield County (1)
- Petroleum County (2)
Which code covers where you are now? What area code am I in? answers from your location.
Questions about area code 406
Where is area code 406?
Area code 406 is in Montana. It covers Billings, Missoula, Great Falls and 537 other places: 386 ZIP codes in Yellowstone, Gallatin, Missoula and 53 other counties.
What ZIP codes are in area code 406?
386 ZIP codes, by the town each is mailed to: Billings (14, 59101 to 59117), Missoula (8, 59801 to 59812), Great Falls (5, 59401 to 59406), Bozeman (6, 59715 to 59772) and 338 more towns. The full list is on this page.
What time zone is area code 406 in?
Mountain time.
Is a 406 number a mobile or a landline?
It can be either. 28% of 406 numbers are assigned to mobile carriers and 41% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.
Does a 406 number mean the caller is in Montana?
Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 406 call can come from anywhere.
All 1 Montana area codes, by area, with the cities each covers
Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.
Cite this page
zipcodes.pro. “Area code 406.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/406
Underlying data is public domain or openly licensed — sources, vintages and licences.