Tokyo MoU – Revised Method of Calculating Flag and RO Performance

C26048 | 26 Oct 2026

Notice to: Ship Owners / Managers / Operators / Masters

The Tokyo MoU issued a press release on 9 October 2026 announcing changes to the method of calculating Flag State and Recognized Organization (RO) performance. The revised methodology will be used to determine ship risk profiles under the New Inspection Regime (NIR).

New Method of Calculating Flag State and RO Performance

Performance will be determined by comparing each Flag State’s or RO’s detention rate with the regional average detention rate, generally based on the latest three calendar years, subject to transitional arrangements for the initial calculation of RO performance.

• Flag or RO whose detention rate is smaller than the regional average detention rate is ‘high’;
• Flag or RO whose detention rate is greater than or equal to the regional average detention rate and less than twice the regional average detention rate is ‘medium’; or
• Flag or RO whose detention rate is greater than or equal to twice the regional average detention rate is ‘low’.

Only one detention will be counted for each Flag State or RO per inspection, irrespective of the number of detainable deficiencies.

For smaller fleets, where the number of inspections during the relevant period is below the critical threshold of 100 divided by the regional average detention rate, performance will be classified as follows:

• Flag or RO who has no detention during the period is ‘high’;
• Flag or RO who has one detention during the period is ‘medium’; or
• Flag or RO who had more than one detention during the period is ‘low’.

Related Recognized Organization (RO)

The term “Related RO” will replace “Responsible RO” for the calculation of RO performance. The Related RO will be the RO that most recently issued or endorsed the statutory certificate associated with a detainable deficiency, as identified using the Background Table for RO Relation published on the Tokyo MoU website. Data on the Responsible RO will continue to be collected for the Tokyo MoU’s internal use.

Implementation Timeline

Collection of data on RO relations will commence on 1 January 2027. For inspections carried out on or after this date, Port State Control Officers (PSCOs) will use the Background Table to identify the statutory certificate related to each detainable deficiency. Flag State data collection will remain unchanged.

Flag State and RO performance will be published in the Tokyo MoU Annual Report approximately on 1 May each year and applied to ship risk profiles under the NIR from 1 July onwards.

For the initial implementation, the following timeline applies:

• Calculation of the flag and RO performance for 2027 using data from 1 January 2025 to 31 December 2027 for Flag States, and from 1 January to 31 December 2027 for ROs;
• Publication of the flag and RO performance in the Tokyo MoU Annual Report on approximately 1 May 2028; and
• Application of the revised performance assessments for ship selection under the NIR on or after 1 July 2028.

Act now

Ship Owners / Managers / Operators are advised to inform their Masters of the revised Tokyo MoU methodology and ensure that vessels maintain compliance with applicable statutory requirements to minimize detainable deficiencies and the potential adverse impact on ship risk profiles under the New Inspection Regime (NIR).