Air carriers are required to be designated as an 'Air Cargo or Mail Carrier operating into the Union from a Third Country Airport' (ACC3) for each non-EU airport from which they fly cargo or mail into the EU. The ACC3 requirements are waived for cargo and mail operations from origins with robust aviation security measures and with an established low risk, as identified through an EU Risk Assessment.

As of 1 July 2014, the EU requires that ACC3s ensure that an EU aviation security validation of its cargo and mail operations at the relevant non-EU airport(s) has been carried out by an EU aviation security validator. The EU aviation security validator will examine the air carrier's security programme to ensure its relevance and completeness and will assess the implementation of aviation security measures during an on-site verification of the cargo and mail operations of that air carrier in non-EU countries.

ACC3s must ensure that all cargo and mail carried to the EU is physically screened or comes from a secure supply chain  which is EU aviation security validated. Also from 1 July 2014, screening needs to take place according to EU standards.

If the air carrier does not comply with these requirements, it will not be designated as ACC3 by the appropriate authority of an EU Member State and will subsequently not be allowed to fly cargo and mail into the EU from a non-EU airport. The designation is valid for a maximum of 5 years.