ClassNK (Nippon Kaiji Kyokai)

Nippon Kaiji Kyokai, trading as ClassNK, is the Japanese classification society founded in 1899 and a founding member of IACS. It is one of the largest classification societies by registered gross tonnage, with particular strength in bulk carriers and tankers. ClassNK issues class and, as a recognized organization for many flag administrations, statutory certificates under SOLAS, MARPOL, and the Load Line Convention. It publishes its own technical rules and guidelines, including guidance on EEDI verification, alternative fuels, and cyber resilience.