The ATA codes, such as LD2, LD3, LD9, and M1, are older and were developed by the Air Transport Association many years ago. These codes have been in use for a long time and are widely recognized in the aviation industry.

The IATA codes, such as AKE, AAP, AMA, RKN, and VGA, are part of the more recent IATA ULD identification system and were developed by the International Air Transport Association. These codes provide a more uniform and standardized approach to ULD identification and are increasingly being adopted by airlines and other stakeholders in the air cargo industry.

The conversion from ATA to IATA codes typically involves updating the ULD identification systems used by airlines, ground handlers, and other stakeholders in the air cargo industry to align with the IATA codes. This process may also involve updating documentation, training materials, and communication systems to ensure that everyone in the air cargo industry is using the same standardized codes.
In general, the use of IATA Identification system codes is preferable.

Conversion ATA/IATA

Note: the 'x' stands for the type code of the IATA ID-Code and could for instance be an 'A' for container, a 'P' for pallet or an 'R' for cool container.