The 406 area code is the single area code serving the entire state of Montana, the fourth-largest state by land area. Assigned in 1947 as one of the original area codes, 406 has covered all of Big Sky Country on its own ever since and has become a strong emblem of Montana identity.
Quick Summary of the 406 Area Code
| Area Code | 406 |
| State | Montana (MT) |
| Region | Statewide Montana |
| Major Cities | Billings, Missoula, Great Falls, Bozeman, Butte, Helena, Kalispell, Havre |
| Time Zone | Mountain Time (MT) – MST / MDT |
| Dialing Format | 7 or 10-digit dialing |
Geographic Coverage
The 406 area code is a statewide code covering all of Montana, including the largest city of Billings in the south-central region, Missoula and Kalispell in the west, Great Falls and Havre in the north, the college town of Bozeman, the mining city of Butte, and the state capital of Helena. It borders Idaho, Wyoming, North Dakota, South Dakota, and the Canadian provinces of Alberta, Saskatchewan, and British Columbia.
Time Zone
The 406 area code observes Mountain Time (MT). Clocks follow Mountain Standard Time (UTC−7) in winter and shift to Mountain Daylight Time (UTC−6) from mid-March through early November. All of Montana is on Mountain Time and observes daylight saving. From the West Coast, this region is one hour ahead of Pacific Time, so a 9:00 AM call in California reaches a 406 number at 10:00 AM local time.
Tip: Business hours across the 406 region generally run 9:00 AM to 5:00 PM local time, Monday through Friday.
How to Dial a 406 Number
Area code 406 is not part of an overlay, and as the only area code in Montana it has traditionally allowed 7-digit local dialing within the state. However, 10-digit dialing is now the recommended nationwide standard, and dialing the full 10-digit number (406 + the seven-digit line number) always works reliably. For international callers, dial your country’s exit code, then +1 (the North American country code), then 406, followed by the seven-digit local number.
Scam Alerts for the 406 Area Code
Like every U.S. area code, 406 has been used by scammers who spoof local numbers to appear trustworthy. Residents across Montana should stay alert to the following common tactics:
| Scam Type | What to Watch For |
|---|---|
| IRS / Tax Scams | Callers claiming you owe back taxes and threatening arrest unless you pay immediately. |
| Utility Shut-off | Fake NorthWestern Energy reps demanding payment to avoid disconnection in winter. |
| Farm / Ranch Scam | Fraudulent online listings for cattle, tractors, or ranch equipment aimed at rural buyers. |
| Bank Fraud Alerts | Robocalls impersonating your bank about “suspicious activity” to phish account details. |
If you receive a suspicious call from a 406 number, take these steps to protect yourself:
- Do not share personal information such as Social Security numbers, bank details, or passwords over the phone.
- Hang up and verify by calling the organization back using an official number from its website.
- Report the call to the FTC at reportfraud.ftc.gov and to the Montana Office of Consumer Protection.
- Block the number and consider registering with the National Do Not Call Registry.
Red Flag: Legitimate agencies such as the IRS, Social Security Administration, or your local utility company (NorthWestern Energy) will never demand immediate payment by gift card, wire transfer, or cryptocurrency. Any 406 caller making such a demand is a scammer.
History and Economy of the 406 Region
n
Area code 406 is one of the original 86 codes established in 1947, and a single code has always served the vast but sparsely populated state. The regional economy is built on agriculture and natural resources – wheat farming and cattle ranching across the eastern plains, coal and oil from the Bakken region in the east, and timber in the west. Tourism is a major and growing force, anchored by Glacier National Park in the northwest, the northern gateway to Yellowstone, and Big Sky skiing. Billings serves as the largest city and a regional healthcare and energy hub, Missoula and Bozeman host the University of Montana and Montana State University, and Bozeman has become one of the fastest-growing towns in the country, drawing technology and outdoor-recreation businesses.
n
Looking Up a 406 Number
n
To identify a 406 caller, use a reverse phone lookup service or search the full 10-digit number online. Many Montana businesses, ranchers, and government offices list their 406 numbers publicly, so a quick search often confirms a legitimate caller. For unknown numbers, let the call go to voicemail – genuine callers usually leave a message, while robocallers and scammers rarely do.
Nearby & Related Area Codes
Montana is served by the single 406 area code, with no overlay. These neighboring area codes are worth knowing:
You can also browse our full directory of Montana area codes for more regional guides.
↑ See the complete list of All US Area Codes by State – every area code across all 50 states in one directory.
Explore Neighboring States
Researching area codes just across the state line? Start with these codes in the states that border Montana:
- Idaho – area code 208
- Wyoming – area code 307
- South Dakota – area code 605
- North Dakota – area code 701
Frequently Asked Questions
Where is the 406 area code located?
The 406 area code covers the entire state of Montana, including Billings, Missoula, Great Falls, Bozeman, Butte, Helena, Kalispell, and Havre.
Does Montana have more than one area code?
No. Montana is served entirely by the single 406 area code, one of the few states covered by just one code with no overlay.
Do I need to dial 10 digits for 406?
As the only area code in Montana, 406 has historically allowed 7-digit local dialing, but dialing the full 10 digits is now the recommended standard and always works.
What time zone is the 406 area code in?
The 406 area code observes Mountain Time (MST/MDT), and Montana does observe daylight saving time.
Related 406 Guides
- Is a 406 call safe? Read Is area code 406 a scam? Spam & safety guide.
- Local coverage: see the Billings area code guide.
- Worried about spam or robocalls? Browse our Scam Alerts directory.