ACC3 stands for “Air Cargo or Mail Carrier operating into the Union from a Third Country Airport”, a designation required in order for these carriers to fly cargo into or through the European Union.
Since July 2014, carrier stations in third countries are required to have undergone an audit to obtain an EU Aviation Security Validation in order to acquire or maintain their ACC3 designation.
This validation needs to be reissued every five years according to the EU Regulation.