In the Carbondale area, 713 represents Verizon Wireless, 203 is a Sprint number, and 303 bares the signature of AT&T Wireless.

But starting Nov. 24 pre-fix signatures are no more.

The Federal Communications Commission recently ordered cell phone companies to disregard their given prefixes and allow for local number portability in the top 100 markets by Nov. 24. Local number portability allows cell phone consumers to carry their phone numbers to a different wireless company in the same area, including the first prefix.

Verizon Wireless Spokeswoman Cheryl Bini said that while the ruling will not have an immediate impact on Southern Illinois, as it is not one of the top 100 markets, it carries indirect ramifications.

Bini said land line companies are eliminating reverse billing, which allowed wireless companies to extend the local calling area by absorbing toll charges from land-line phones to cell phones. But with local number portability, landline companies, like Verizon Communications, do not know which company to bill, placing the charge on the landline phone owner.

“It’s a land line issue; the wireless bill doesn’t change,” Bini said. “And it may not affect you. If you don’t have a lot of incoming calls, don’t worry. If you call from a number that’s not being charged a toll, you don’t need to change numbers.”

Michael Beehn, a spokesman for First Cellular, said that though customers with most wireless companies can change their numbers to avoid toll charges from land-lines, they need to remember that wireless bills will not be affected, and the affect on land-lines is minimal.

“Incoming call represent less than 20 percent of cell phone usage,” Beehn said. “And for those with more, we want to give customers the option to switch to a local number.”

Verizon Communications spokeswoman Tracy Scholle says it is impossible to determine how much the toll charge would cost for landline users, other than it is a normal, long-distance rate. She said it depends on calling patterns, the wireless and wire line companies and duration of call.

“We encourage our customers to be proactive and take advantage of the free options,” she said. “They should find out where their prefix is based and move from there.”

Reporter Katie Davis can be reached at [email protected]