I had a negative account with a utility company. (PG&E) DOFD was in 2002. I paid off the $380 balance in 2006. It just barely rolled off earlier this year. No matter how many GW letters, phone calls and time I spent on it; both CRAs and PG&E refused to remove the trade line associated with the account.
It took just under 8 years for it to roll off.