The IMO Data Collection System (DCS) is the global regime for annual fuel oil consumption reporting from ships of 5,000 GT and above. This guide explains its scope, the SEEMP Part II plan, the Statement of Compliance, and how DCS feeds the CII rating.
The IMO Data Collection System (DCS) is mandated by MARPOL Annex VI Regulation 22A, in force from 1 March 2018 with reporting from calendar year 2019. It requires ships of 5,000 GT and above on international voyages to collect and report annual fuel oil consumption data to the flag state, which in turn forwards the anonymised data to the IMO for the IMO Ship Fuel Oil Consumption Database.
Every ship of 5,000 GT and above engaged on international voyages — approximately 85% of the global fleet by GHG emissions. Small and near-coastal ships are excluded from DCS but may be covered by flag-state national regimes or EU MRV (which captures from 400 GT from 2025).
The backbone of DCS is Part II of the Ship Energy Efficiency Management Plan (SEEMP):
SEEMP Part II is approved by the flag state (or Recognised Organisation) before 31 December of the year preceding the first reporting year.
From 2023, SEEMP Part III (CII plan) sits alongside Part II. It contains the required annual operational CII, the three-year plan to achieve it, and the corrective action if the ship is rated D three years running or E in a single year. See What is the CII Rating?
The DCS SoC must be retained on board alongside the International Energy Efficiency Certificate (IEEC). Port State Control inspections check its validity; missing or expired SoC is a detainable deficiency.
See What is the EU MRV regulation?
The IMO Net-Zero Framework’s Fuel Standard will build on the DCS data-collection backbone. Ships already compliant with DCS will need to layer on Well-to-Wake emission factors per fuel lift to satisfy the emerging GHG Fuel Intensity (GFI) metric. See What is the IMO Net-Zero Framework?
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