Billings, Montana

Where Is Area Code 406?

Area code 406 serves the entire state of Montana, including Billings. It is the only area code in Montana. Billings is the largest city in the state, and it uses area code 406 along with every other Montana community.

Area code 406 covers major cities such as Billings, Missoula, Great Falls, Bozeman, Butte, Helena, and Kalispell. It also covers counties across eastern, central, western, and northern Montana, including Yellowstone County, where Billings is located. Smaller communities across rural Montana also use this area code.

Area code 406 covers a state known for large landscapes and major natural landmarks. Montana includes parts of Yellowstone National Park, Glacier National Park, and the Rocky Mountains. The area code also reaches communities near the Missouri River, Yellowstone River, and wide plains in eastern Montana.

History of Area Code 406

Area code 406 was established in 1947 as one of the original North American area codes. It was assigned to Montana at the start of the North American Numbering Plan. Montana has kept 406 as its only area code since then.

Area code 406 has not been split, and it has not had an overlay. Montana's low population and large rural geography helped the state keep a single area code for decades. In 2023, the Montana Public Service Commission approved a plan to add area code 771 as an overlay because 406 was projected to run out of numbers, but 406 remains in use statewide.

Key Facts About Area Code 406

• Area code 406 is in Montana, and Billings is the state's largest city.
• Area code 406 covers the entire state of Montana, not just Billings.
• Area code 406 was created in 1947 as an original area code in the North American Numbering Plan.
• Area code 406 is in the Mountain Time Zone. Most of Montana observes Mountain Standard Time and Mountain Daylight Time.
• Montana had a population of 1,084,225 in the 2020 United States Census.
• Billings is in Yellowstone County, and Yellowstone County is the most populous county in Montana.
• Montana State University in Bozeman and the University of Montana in Missoula are both in area code 406.
• Glacier National Park, part of Yellowstone National Park, and the state capital of Helena are all within area code 406.

Frequently Asked Questions

What state is area code 406 in?

Area code 406 is in Montana.

What major cities use area code 406?

Major cities in area code 406 include Billings, Missoula, Great Falls, Bozeman, Butte, Helena, and Kalispell.

Is area code 406 a toll-free number?

No. Area code 406 is a geographic area code for Montana.