Operational Guide · Registers & Logbooks

# IMO DCS: Transport Work and Advanced Granularity from 2026

Ships that have not adopted advanced data collection on a voluntary basis since January 2025 must do so mandatorily from 1 January 2026: total fuel consumption alone is no longer enough — detail per individual onboard consumer is required.

IMO DCS MARPOL Annex VI transport work data granularity

## Operational Explanation

Resolution MEPC.385(81) introduced two additional data categories into the Ship Fuel Oil Consumption Database (IMO DCS): transport work data (the transport work actually carried out, not just distance travelled) and advanced fuel consumption granularity, broken down by individual onboard consumer group (main engine, auxiliary engines, boilers) and by operating condition (underway/not underway).

Ships of 5,000 GT and above that have not started advanced data collection on a voluntary basis since January 2025 are required to do so from 1 January 2026. A further change concerns data transparency: all data reported under IMO DCS will be accessible to Annex VI Parties in non-anonymised form, while an anonymised database will continue to be publicly available.

## Regulatory Reference

MARPOL Annex VI, Chapter 4 — amendments under Resolution MEPC.385(81), in force since 1 August 2025, with full mandatory advanced data collection (transport work and per-consumer granularity) from 1 January 2026 for ships that have not opted in voluntarily since January 2025.

## Scope of Application

Every ship of 5,000 GT and above subject to IMO DCS under MARPOL Annex VI Chapter 4, with the Company responsible for adapting onboard data-collection systems to the new granularity requirements.

## Procedure / How to Complete It

1. Check whether the ship has already opted into advanced data collection on a voluntary basis since January 2025; if not, arrange the necessary adaptation by 1 January 2026.
2. Adapt onboard systems to record fuel consumption separately for the main engine, auxiliary engines and boilers.
3. Record consumption separately for underway and not-underway conditions, no longer as a single aggregate figure.
4. Arrange for the collection of transport work data (actual transport work performed), distinct from the distance-travelled data collected previously.
5. Inform the crew and the technical office that reported data will now be accessible in non-anonymised form to Annex VI Parties, with implications for transparency towards Flag Administrations.

## Practical Example

Example: an 8,000 GT ship that until now recorded only total monthly fuel consumption arranges, by 1 January 2026, a monitoring system that separates main engine consumption from that of auxiliary engines and boilers, and distinguishes underway hours from not-underway hours, in line with the new IMO DCS granularity requirements.

## Real Cases

Ships that postponed adapting their data-collection systems, treating the voluntary January 2025 opt-in date as non-binding, now find themselves having to complete technical implementation on a tight schedule before the mandatory 1 January 2026 deadline — an adaptation that takes time to configure onboard monitoring systems and cannot be improvised at the last minute.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Adaptation of data-collection systems postponed by relying solely on the mandatory 2026 deadline, without considering implementation lead times | Systems not ready in time, risk of non-compliance with the 1 January 2026 deadline | Start adapting monitoring systems well ahead of the mandatory deadline
Fuel consumption data continued to be collected in aggregate form, without breakdown by consumer or operating condition | Non-compliance with the new IMO DCS granularity requirements | Always adapt onboard systems to the required breakdown by consumer (main engine, auxiliaries, boilers) and operating condition
Implications of non-anonymised data transparency towards Flag Administrations not communicated internally | Organisational surprise once the data becomes visible to Annex VI Parties | Inform the technical office and the Company in advance of the new level of data transparency

## PSC Observations

Compliance with IMO DCS granularity requirements is not typically the subject of direct, immediate PSC verification, but the currency of SEEMP Part II and the consistency of collected data may be checked as part of general inspections of environmental documentation.

## Operational Tips

- Do not wait for the 1 January 2026 deadline to adapt data-collection systems: implementation takes time and requires lead time.
- Always verify that the onboard system separates consumption by main engine, auxiliaries and boilers, and by underway/not-underway condition.
- Inform the technical office in advance that reported data will now be accessible in non-anonymised form to Annex VI Parties.

## Checklist

- 2025 voluntary opt-in or 2026 mandatory adaptation need verified
- Onboard system adapted to break down consumption by individual consumer group
- Consumption separately recorded for underway/not-underway conditions
- Transport work data collection arranged
- Implications of non-anonymised data transparency communicated internally

## FAQ

Since when is advanced IMO DCS data collection mandatory for all ships?
From 1 January 2026, for ships of 5,000 GT and above that have not already opted in voluntarily since January 2025.
What is meant by transport work data?
The transport work actually carried out by the ship, a distinct and more complete metric than the distance-travelled data previously collected under IMO DCS.
Will IMO DCS data be publicly visible?
Complete, non-anonymised data will be accessible to Annex VI Parties; an anonymised database will, however, continue to be publicly available.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

MARPOL Annex VI Fuel Oil Changeover

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