Distribution box certification typically requires compliance with IEC 61439 5 for low-voltage assemblies, UL 50/508A 6 in North America, EN 61439 in Europe, and GB 7251 7 in China. It is a key resource for complying with National Motor Freight Classification (NMFC®) rules. The BMC tells shippers exactly what a corrugated box is rated to carry, providing information about the carton's strength, structure, and compliance with industry standards. In this article, we'll explain what the BMC is, why it matters, and how it relates. Sometimes called a box cert, cert stamp, or box certificate stamp, a BMC is a printed label that appears on the bottom or flap of a corrugated shipping box.