What Is Area Code 406? (Billings, Montana)

Area code 406 covers Billings and surrounding areas in Montana. It is one of the original 86 area codes established by AT&T in 1947. For the full picture, see all Montana area codes.

Quick Facts: Area Code 406

State	Montana
Primary city	Billings
Cities also served	Billings, Missoula, Great Falls, Bozeman, Helena, Kalispell, Butte, Havre
Time zone	Mountain (UTC-7 / UTC-6 DST)
Year established	January 1, 1947
Original 1947 NPA?	Yes
Overlay codes	None
Currently in use?	Yes, actively assigned
Ten-digit dialing required?	Local seven-digit dialing may still apply

Cities Served by Area Code 406

Area code 406 serves Entire state of Montana, including the following cities and communities:

• Billings
• Missoula
• Great Falls
• Bozeman
• Helena
• Kalispell
• Butte
• Havre

How to Get a 406 Phone Number

There are three ways to get a phone number with the 406 area code, each suited to a different need:

1. Buy from a premium-number specialist. Companies that hold curated inventories of specific area codes can sell you a 406 number directly, often with a one-time fee and ownership transferred to you (no recurring carrier fees). This is the option for picking a specific memorable number, or for getting an area code that most carriers won’t let you request. Browse our 406 inventory.
2. Sign up with a VoIP carrier. Voice-over-IP services (such as Google Voice, OpenPhone, Grasshopper, and many others) can typically provision a 406 number on request, especially for active overlay codes. You won’t usually get to pick the specific number, but you’ll get a working line in the area code. This is the cheapest option for anyone who doesn’t need a particular number.
3. Port an existing 406 number. If you already have a 406 phone number with another carrier, you can transfer it (port it) to a new service provider while keeping the number. This works for landlines, cell phones, and VoIP services, though landlines outside of Montana sometimes can’t accept inbound ports of 406 numbers due to 911 routing rules.

Looking for a 406 number? 212areacode.com offers premium 406 numbers for Billings, Montana — choose your number, port it to any carrier in 3–5 business days, and pay a one-time fee with no monthly charges. Browse available 406 numbers →

Frequently Asked Questions

Is the 406 area code still in use?
Yes. 406 is actively assigned to new phone lines in Entire state of Montana.

Can I get a 406 number if I don't live in Montana?
Yes. Phone numbers are no longer tied to a physical address. With VoIP service or a number broker, you can hold a 406 number from anywhere in the world. The number routes to whatever device or carrier you specify.

Is 406 a scam area code?
No. 406 is a legitimate, active area code for Entire state of Montana. Like any area code, scammers occasionally spoof 406 caller IDs, but the code itself is heavily used by real Montana businesses, government offices, and residents.

Does Montana have more than one area code?
No. Montana is served exclusively by area code 406, making it one of roughly eleven U.S. states that still operate with a single area code as of 2026.

Has area code 406 ever been split or overlaid?
No. Area code 406 has never been split or received an overlay code. It has covered the entire state of Montana without change since January 1, 1947.

Is ten-digit dialing required in the 406 area code?
Yes. Ten-digit dialing (1 + 406 + seven-digit number) is required for calls within Montana, a requirement tied in part to the 2021 reassignment of the 988 prefix as the national mental health crisis line.

What is '406 Day'?
April 6 (4/06) is celebrated informally by many Montanans as ‘406 Day,’ an unofficial holiday that uses the state’s iconic area code as a symbol of Montana pride.

Related Reading

• How Do Area Codes Work?
• How Are Area Codes Assigned?
• Why the Right Area Code Matters
• When Did We Start Using Area Codes?

See where it sits in the full US area code directory.