N.C. Gen. Stat. § 66-425

Limitation on Cash Purchases. No nonferrous metals purchaser shall enter into a cash transaction for the purchase of copper, and no nonferrous metals purchaser shall purchase any nonferrous metal property for any cash consideration greater than one hundred dollars ($100.00) per transaction. Any payment in excess of one hundred dollars ($100.00) per transaction shall be made by check, money order or cash card system. A nonferrous metals purchaser shall not make more than one cash purchase per day from any individual, business, corporation or partnership.