Montana is one of the last states with a single area code and the Montana Public Service Commission hopes to keep it that way, recognizing how popular the 406 area code has become in the state’s identity.

Recently, the Public Service Commission voted unanimously to take a step to try to make sure one area code will work for a lot longer. They sent a letter to Qwest Corporation, a telecommunications company that controls at least a couple of pieces of the puzzle, according to the Daily Montanan.

Montana could run out of 406 phone numbers by 2033. It’s not because all the numbers will be in use by far. 

The report says that this isn’t the first time the PSC has taken up the issue of the 406 area code. In 2013, the PSC received federal permission to implement a more efficient way of assigning numbers, and it ordered telecommunications companies to follow it. The action allowed the continuation of Montana being the “406 state” for quite a while.

Alaska, the Dakotas, and Wyoming are among the states that still have a single area code.

The North American Numbering Plan Administrator oversees the distribution and use of telephone numbers across North America, and it’s the organization that projects Montana will run out of 406 numbers in the first quarter of 2033.

The PSC is requesting that Qwest provide an analysis of “rate center consolidation,” which is basically, a different way to distribute and “conserve” phone numbers.

The memo described the different parts of a phone number — the area code, then, the NXX code, and the four-digit line number. (For example, the PSC’s NXX number is 444, with a phone number of 406-444-6150.)

“In Montana, it is the dwindling number of unused NXX codes that is causing the state to run out of telephone numbers,” according to the PSC staff.

The maximum number of NXX codes available for telephone companies to use is 786, and of those, 753 are already in use, according to the staff memo. That means only 33 NXX codes are left for Montana.

It is likely the total telephone numbers that are actively in-service for Montana’s 406 area code is less than 50% of total available numbers, reports the PSC.

In its letter, the PSC asks Qwest to provide an analysis of a consolidation of its rate centers into each of the state’s two districts, including how it would work technically; its operational efficiencies or inefficiencies; call routing impacts; and timelines and cost.

PSC Vice President Jennifer Fielder supported the move to send the letter to Qwest, but she also cautioned that promising that Montana remains the 406-only state wasn’t a sure bet because the Commission doesn’t control all the factors.