From 2023, cargo, cruise and RoPax ships should calculate CII with a required rating of C or better. This means some ships will have to improve their carbon intensity. A verified Ship Operational Carbon Intensity Plan, or SEEMP Part III, is to be kept on board from 1 January 2023 to document how you plan to achieve your CII targets.

The Carbon Intensity Indicator (CII) and operational carbon intensity rating

The attained CII is the CO2 emitted per capacity transport work during a calendar year, adjusted by correction factors (to be finalized at MEPC 78 in June) that will be available for some ship types and operations.

The carbon intensity indicator

Based on its attained CII, a vessel will be rated annually from A to E, where A is the best and C the minimum rating.

The rating system will be the primary mechanism to achieve the IMO’s ambition to gradually reduce the carbon intensity of international shipping to at least 40% by 2030 relative to 2008. The required CII, and thereby the rating thresholds, will be reduced year-by-year. The reduction rates are set for 2023 to 2026, and subsequent reduction factors will be set during a review in 2025.

Required annual operational CII

The purpose of the SEEMP Part III

The SEEMP Part III, or Ship Operational Carbon Intensity Plan, will serve as the implementation plan for achieving the required CII and will be subject to verification and company audits. The SEEMP Part III will be a dynamic plan, as it will be subject to regular updates and revisions. 

DNV has launched the SEEMP Part III Generator. The generator is an online tool, reducing your paperwork and efforts, and can be used by both ship managers and third-party consultants working on behalf of DNV DCS customers. More information can be found here.

The CII and SEEMP III timeline in short

  • The first DCS reporting year for which a CII will be calculated is 2023, and the first rating will be given in the first half of 2024 based on the 2023 reporting year. Then, the first milestone when a verified SEEMP III shall be on board is 1 January 2023.
  • From 2024, the CII must be calculated (Recommendation: DNV’s Emissions Insights tool) and reported to the DCS verifier together with the aggregated DCS data for the previous year prior to 1 April, including any correction factors and voyage adjustments.
  • The CII will be verified together with the aggregated DCS data (Recommendation: DNV’s DCS platform which allows you to upload your raw data whenever it suits you – removing the need for manual data aggregation and submission).
  • The SoC will be issued prior to 1 June as per today; the only difference is that the attained CII and the rating will be noted, and it will be required to keep the SoC on board for five years.
  • In case of an inferior rating, meaning a D rating for three consecutive years or one E rating, the SEEMP III must be updated with a corrective action plan and verified before the SoC is issued. The corrective action plan should consist of an analysis of why the required CII was not achieved and include a revised implementation plan.


We recommend to start checking the status of the CII rating today and identify possible measures that may be implemented to achieve the target rating for the next three years. Our DCS customers can visit the Emissions Insights tool (Learn more & watch a short demo) for an overview of the status and the impact on future ratings for the fleet and ships as well as access the SEEMP Part III Generator. The SEEMP Part III Generator is available under MyFleet on Veracity.

Fit for 55 New EU GHG regulations

Discover DNV's DCS platform and Emissions Insights

Plug in to a seamless journey to decarbonization

Learn more on CII

Visit our topic page

Learn more on MRV and DCS

Visit our topic page including many FAQs