EEXI and SEEMP Part III: what they require, the reduction factors and the surveys

Each ship in the listed types, including one that has undergone a major conversion, calculates an attained EEXI following IMO’s 2022 calculation guidelines (resolution MEPC.350(78)), documents it in an EEXI technical file, and has it verified. The attained value must not exceed the required EEXI:

Attained EEXI ≤ Required EEXI = (1 − Y/100) × EEDI reference line value

Y is the reduction factor for the ship type and size (table below). IMO describes the required EEXI as equivalent to the required EEDI levels for 2022. A ship that already has a verified attained EEDI at or below its required EEXI may use that EEDI value as its attained EEXI.

How ships comply: IMO lists engine or shaft power limitation, waste heat recovery and wind-assisted propulsion among the existing technologies, and says the owner or charterer chooses the means. Its guidelines on shaft/engine power limitation systems and use of a power reserve are resolution MEPC.335(76).

Sources: IMO, MARPOL Annex VI regulations 23 and 25, Improving the energy efficiency of ships and EEXI and CII FAQ; read on 13 November 2026.

Every ship of 400 gt and above keeps a ship-specific SEEMP, which may form part of its Safety Management System. IMO names three parts: Part I, the ship management plan to improve energy efficiency; Part II, the fuel oil consumption data collection plan (ships of 5,000 gt and above, for the IMO Data Collection System); and Part III, the ship operational carbon intensity plan. For ships of 5,000 gt and above in the CII ship types, the SEEMP had to include, on or before 1 January 2023:

1. the method for calculating the ship’s attained annual operational CII and the process for reporting it to the Administration;
2. the required annual operational CII for the next three years;
3. an implementation plan showing how that required CII will be achieved over the next three years; and
4. a procedure for self-evaluation and improvement.

Verification: Part III is subject to verification and company audits (regulation 26.5). The Administration had to confirm compliance before 1 January 2023, and the confirmation of compliance is kept on board. The attained CII is reported within three months after the end of each calendar year.

When the rating is poor: a ship rated D for three consecutive years, or rated E, revises its SEEMP to include a plan of corrective actions (regulations 26.3.2 and 28.8). The SEEMP guidelines referred to in the consolidated text are the 2024 Guidelines (resolution MEPC.395(82), as amended by MEPC.401(83)).

Sources: IMO, MARPOL Annex VI regulations 5.4.6, 26 and 28.2 and Improving the energy efficiency of ships; read on 13 November 2026. Paraphrased; MARPOL Annex VI is authoritative.

• Review phase 2, spring 2026 to spring 2028: IMO says it will further develop the SEEMP framework and metrics, alongside the CII rules. Nothing changes on board until amendments are adopted and enter into force.
• EEXI: regulation 25 is kept under review in light of its implementation and IMO’s GHG strategy.
• Net-Zero Framework: a separate, not-yet-adopted package would add further SEEMP content later; see the IMO Net-Zero Framework.

Sources: IMO, EEXI and CII FAQ and regulation 25.3; read on 13 November 2026.