On MEPC 76 (17th of June 2021), the International Maritime Organisation (IMO) adopted amendments to MARPOL annex VI, based on MEPC 75 suggestions, which contributed to the new regulations 23 and 25, which guides abouts the introduction of EEXI (Energy Efficiency Existing Ship Index) and regulation 28 talking regarding CII (Carbon Intensity Indicator).


CII is an obligatory measure since 1st of January 2023 for all cargo, Ro Pax and cruise vessels above 5000 gross tonnage and trading internationally.

​The EEXI is a carbon design/ technical efficiency indicator, whereas CII is an in-service/ operational efficiency indicator. In simple words it can be said that, the vessels have to document and also to be recorded in the Ship’s Energy Efficiency Management Plan (SEEMP) and report their carbon use, which will be used to give them an efficiency rating, known as the CII.


The CII determines the annual reduction factor needed to continuously improve and keep the carbon intensity with in the specific rating level. The actual operational CII reported should be verified against the required annual operational CII. 

​The rating would be given on a scale – operational carbon intensity rating A, B, C, D or E – indicating a major superior, minor superior, moderate, minor inferior, or major inferior, performance level.


A ship continually rated D for three years or E rating in a single year will require to submit a remedial action plan to show how to acquire index rating C or above.Administrations, port authorities and other stakeholders as appropriate, are encouraged to provide incentives to ships rated as A or B.

Reference: imo media centre press briefings CII and EEXI entry into force.

Author: Aparna Raju