SPRINGFIELD, Ill. (WAND) - A new area code will be implemented for the 217 region. 

The 447 prefixes will start after March 29, 2021. The Illinois Commerce Commission announced the news on Monday. 

The new 447 area code will "overlay" the existing 217 area code to address depletion of the 217 prefix. 

The 217 area code covers 36 counties in Illinois and includes communities such as Springfield, Champaign, Urbana, Decatur, Danville, Quincy, and Rantoul. The 217 area code is one of the original, eighty-six area codes in the United States, assigned by Bell Laboratories in 1947. It has not undergone any substantive changes to its boundaries nor its dialing patterns since 1951. 

A petition for a new area code was filed in June of 2001. The code was approved in 2007 to be used in in the area code 217. Ongoing conservation efforts have forestalled the need to release the new area code until 2021. 

Many 217 telephone numbers are still unassigned in the area. The code is deemed to be "exhausted" when the last available prefix has been assigned. 

Current 217 users will retain the original code. New phone numbers may receive a number with the new overlay area code. 

The FCC requires all calls made in the overlay area to be completed by dialing the full, 10-digit number (area code + seven-digit number).  This includes calls currently dialed with seven digits in the existing area code. This requirement does not affect the cost of the call. A local call will remain a local call, and a toll call will remain a toll call, regardless of the number of digits that are dialed to complete it.

Prior to the assignment of numbers in the new area code, customers in the 217 area code will have a six-month period time, between August 29, 2020 and February 27, 2021, to adjust to dialing the additional digits to complete their calls, prior to it becoming mandatory. During this period, consumers are encouraged to update their contact lists and auto dialers to include the 10-digit number. After February 27, 2021, all calls must be dialed with the Area Code + Telephone number.