N.C. Gen. Stat. § 58-70-85: Application of funds where there is a debtor-creditor relationship.

If a creditor has listed accounts with a permit holder for collection and also has had accounts on which he is debtor listed with the permit holder by any other creditors, collections effected in his behalf as a creditor may not be applied on accounts that he owes unless the permit holder has a written authorization on file as to how the moneys collected are to be applied. (1979, c. 835.)