Central Oregon’s new telephone area code won’t kick in until early next year, but starting July 12, officials want residents to start dialing more digits when they make calls.

Last year, the Oregon Public Utilities Commission decided it was time for most of the state to get a new area code, because officials believe the 541 area code will run out of numbers by 2011. The 541 area code covers all of the state, except the northwest corner, which is assigned the 503 and 971 area codes.

The new area code, 458, will cover the entire 541 region, but will not affect numbers that already exist. Bob Valdez, a commission spokesman, said phone companies won’t start issuing numbers with a 458 area code until Feb. 10, but people will need to start using area codes for all numbers — even calls within the same city — on Jan. 10.

But Valdez said the commission is suggesting people should start dialing all 10 digits this summer, so they’ll be ready for the transition next winter.

“It’s not mandatory, but we’re just encouraging folks to do it so they can get an early start,” he said. “If you want to be an early adopter, you’ll have one fewer thing to worry about next year.”

Valdez said local calls that don’t include the area code will still go through until January.

Until the mid-1990s, the entire state of Oregon used the 503 area code. When the state’s second area code, 541, was created in 1995, people in Southern, Central and Eastern Oregon had to change their numbers.

In 2000, the PUC added a 971 overlay to sections of the 503 area code region, including Portland and Salem, and in 2008, added the northwest coast to the overlay zone.

Valdez said the 971 overlay zone has worked well, and officials don’t expect any problems when 458 numbers start popping up here. He said adding new area codes with overlay zones has proved to be easier than adding several additional numbers in different areas in the state.

“It makes it easier for people to understand, rather than cutting the state up into little slices,” he said.

Despite the change in area codes, the cost of calls will not change because of the area code. And calling emergency and information numbers, such as 911 or 411, will remain the same, according to documents on the commission’s Web site.