DENVER - When Mark Walters received a $2,500 bill from his long-distance carrier, Denver-based Qwest, he figured it had to be a mistake. It was, and it was his daughter's boo-boo.

Elissa Walters, 18, had gone home to Springfield, N.J., for Christmas break, turned on a new computer and called an America Online number in the 973 area code - the Walters' home area.

Figuring it was a free local call carried by their local carrier, Verizon Communications, she left the computer on. And on. And on.

But just because the area code was the same, it didn't mean the call was local.

"The bottom line is it's a toll call," said Qwest spokesman Skip Thurman. The usual way to tell is if you have to punch "1" before the area code, although that isn't always the case in some East Coast service areas, Thurman said.

Mark Walters learned all of this when his bill arrived six weeks ago.

He begged for a break, saying even $500 would be fair - enough to teach Elissa a lesson without bankrupting her, but said a representative named Bob told him last week that wouldn't happen