Blister copper is the crude product of copper smelting — roughly 98–99% pure, with a blistered surface from escaping sulfur gases — and is an intermediate that may be further refined or cast into anodes. Copper anodes are cast from blister or other unrefined copper specifically for electrolytic refining. Both forms are included in this heading, as neither has undergone electrolytic refining to produce refined cathode copper.

Copper anodes imported for further processing into refined copper may be eligible for manufacturing drawback if the resulting refined copper or byproducts are subsequently exported. Importers should work with a licensed customs broker to structure the entry correctly — bonded warehouse or temporary importation bond programs may also be relevant depending on the refinery's operational model and the origin of the anodes.