An American maritime classification society established in 1862. As of 2020, ABS was the second largest class society with a classed fleet of over 12,000 commercial vessels and offshore facilities.

A French company specialized in testing, inspection and certification since 1828. Bureau Veritas is present in 140 countries through a network of over 1,500 offices and laboratories, and more than 78,000 employees.

An international accredited registrar and classification society headquartered in Høvik, Norway. DNV is the world's largest classification society, providing services for 13,175 vessels amounting to 265.4 million gross tonnes, which represents a global market share of 21%.

International ship classification society providing ship classification and certification as well as technical inspection services. The not for profit entity was founded in 1975. IRClass took over Chairmanship of the International Association of Classification Societies (IACS) effective July 1, 2019.

Not-for-profit classification society founded in South Korea offering verification and certification services for ships and marine structures in terms of design, construction and maintenance. Founded in 1960, the society employs 889 people.

The organisation dates to 1760. Lloyd's Register's main office is located in London at 71 Fenchurch Street. Lloyd's Register also operates in more than 70 locations, serving clients based in 182 countries.

It is also known by the brand name “ClassNK”, based in Tokyo Japan, founded 1899. On 28 May 2012, ClassNK officially announced that its register had surged past the 200 million gross ton mark becoming the world’s first class society in history to have more than 200 million gross tons on its register.

RINA is a private, multinational company headquartered in Genoa, Italy. It was founded in 1861 and is one of the founding members of IACS. Today, RINA has a network of over 200 offices in 70 countries worldwide with a workforce of 4000 people.