N.C. Gen. Stat. § 115C-439

The board of education may provide by appropriate resolution for the use of facsimile signature machines, signature stamps, or similar devices in signing checks and drafts and in signing the preaudit certificate on contracts or purchase orders. The board shall charge the finance officer or some other bonded officer or employee with the custody of the necessary machines, stamps, plates, or other devices, and that person and the sureties on his official bond are liable for any illegal, improper, or unauthorized use of them.