Port State Control

Port State Control (PSC) is the inspection of foreign ships in national ports to verify that the condition of the ship and its equipment comply with the requirements of international regulations and that the ship is manned and operated in compliance with these instruments and ensure maritime safety and security and prevent pollution.

PSC inspections are intended to be a backup to flag State implementation, a “second line of defence” against substandard shipping, and experience has shown that they can be extremely effective. The Organization adopted resolution A.682(17) on Regional co-operation in the control of ships and discharges promoting the conclusion of regional agreements.

Many IMO conventions contain provisions for Governments to inspect foreign ships that visit their ports to ensure that they meet IMO standards contained in instruments to which the port State is a Party, taking into account the concept of no-more favourable treatment. If they do not, they can be delayed or detained until repairs are carried out and be subject to targeting.

For ships travelling to different countries in the same region, a regional coordinated inspection that focuses on substandard ships and avoids multiple inspections can be more efficient and cost effective to member States, as well as providing a level playing field to ports of the region. The harmonization of PSC inspections aims at ensuring that as many substandard ships as possible are inspected and at preventing ships from being subjected to multiple inspections. The primary responsibility for ensuring ships' standards rests with the flag States.

When a PSC Officer (PSCO) inspects a foreign ship, any such inspection should be limited to verifying that there are on board valid certificates and other relevant documentation, unless there are "clear grounds" for believing that the condition of the ship or its equipment does not correspond substantially with the particulars of the certificates.

If the PSCO identifies clear grounds for believing that the condition of the ship or its equipment does not correspond substantially with the particulars of the certificates or that the master or crew is not familiar with essential shipboard procedures, a more detailed inspection should be carried out. When exercising control, all possible efforts should be made to avoid a ship being unduly detained or delayed.  

For more details, please refer to the Procedures of Port State Control, 2023 (resolution A.1185(33)).

Legal Framework of Port State Control

Article 218 (1), Enforcement by port States, of the United Nations Convention of the Law of the Sea (UNCLOS) states, “When a vessel is voluntarily within a port or at an off-shore terminal of a State, that State may undertake investigations and, where the evidence so warrants, institute proceedings in respect of any discharge from the vessel outside the internal waters, territorial sea or exclusive economic zone of that State in violation of applicable international rules and standards established through the competent international organization or general diplomatic conference.”. Article 219, Measures relating to seaworthiness of vessels to avoid pollution, stipulates that “States which, upon request or on their own initiative, have ascertained that a vessel within one of their ports or at one of their off-shore terminals is in violation of applicable international rules and standards relating to seaworthiness of vessels and thereby threatens damage to the marine environment shall, as far as practicable, take administrative measures to prevent the vessel from sailing. Such States may permit the vessel to proceed only to the nearest appropriate repair yard and, upon removal of the causes of the violation, shall permit the vessel to continue immediately”.

The requirements contained in IMO conventions comprise SOLAS 1974 regulations I/19, IX/6.2, XI-1/4 and XI-2/9, as modified by SOLAS PROT 1988; article 5 and 6, regulation 11 of Annex I, regulation 16.9 of Annex II, regulation 9 of Annex III, regulation 14 of Annex IV, regulation 9 of Annex V and regulation 10 of Annex VI of MARPOL; article X of STCW 1978; article 12 of TONNAGE 1969, article 11 of AFS 2001 and article 9 of BWM 2004, on control procedures be followed by a Party of a relevant convention with regard to foreign ships visiting their ports. Effective use of these provisions by the authorities of port States can identify deficiencies onboard foreign ships which may render them substandard and ensure that remedial actions are taken.

Port State Control Regimes 

Currently, there are ten PSC regimes, comprising eight regional Memoranda of Understanding (MoUs), and one Agreement on port State control covering specific regions (i.e. Europe and the north Atlantic (Paris MoU); Asia and the Pacific (Tokyo MoU); Latin America (Acuerdo de Viña del Mar); Caribbean region (Caribbean MoU); West and Central Africa (Abuja MoU); Black Sea (Black Sea MoU); Mediterranean Sea (Mediterranean MoU); Indian Ocean (Indian Ocean MoU); and Persian Gulf (Riyadh MoU)) and the United States Coast Guard forming the tenth PSC regime. Some member countries belong to more than one PSC regime. All regional PSC regimes have acquired the observer status at IMO, as intergovernmental organizations (IGOs). Their representatives attend IMO meetings and, in particular, introduce vast amounts of information on their annual activities in the form of documents submitted to every session of the Sub-Committee on Implementation of IMO Instruments (III Sub-Committee, formerly the Sub-Committee on Flag State Implementation (FSI)). The information provided can support the assessment of the fitness of and compliance with IMO standards, and the IMO rule-making process.

A typical organizational structure of a regional PSC regime has three components: the Port State Control Committee, the Secretariat, and the database or information system. Each regional PSC regime holds its Committee meeting annually with its member Authorities, co-operating member Authorities, and observer organizations. IMO is an observer organization to all regional PSC regimes. Several technical cooperation activities are implemented in cooperation with PSC regimes in the context of outreach partnership. In this context, IMO sponsored the participation of PSCOs from developing PSC regimes at training courses organized by the Tokyo, Paris and Indian Ocean MoUs, the most recent one being the Ninth General Training Course, organized by the Tokyo MoU in Japan, from 19 August to 13 September 2019.

The Organization signed electronic data exchange agreements with PSC regimes so that the regional information system can provide relevant inspection data to the Global Integrated Shipping Information System (GISIS) PSC module on behalf of the member countries.

IMO is also a member of the Editorial Board and an observer of the Supervisory Committee of the Equasis (Electronic Quality Shipping Information System) which compiles PSC data.

Sub-Committee on Implementation of IMO Instruments (III) and Measures to Harmonize PSC Activities and Procedures Worldwide 

The III Sub-Committee usually establishes, as per its agenda, the Correspondence and Working Groups on Measures to Harmonized Port State Control (PSC) Activities and Procedures Worldwide.   

The Groups are tasked to develop and update PSC procedures and guidelines with a view to harmonizing PSC activities globally. They also consider and discuss issues raised in the context of PSC activities, such as implementation of IMO instruments and amendments thereto, concentrated inspection campaigns, PSC data management and information exchange, statistics and analysis of PSC activities and data and PSCO training activities. For more details about progress of the Groups, please refer to relevant documents under the III Sub-Committee on IMO IMODOCS website.

Procedures of Port State Control 

The Organization has always recognized that efforts by port States have greatly contributed to enhance maritime safety and security, and prevention of marine pollution. The Organization adopted resolution A.1185(33) on Procedures for Port State Control, 2023, following successive revocation of resolutions A.1155(32), A.1138(31), A.1052(27), A.882(21), A.787(19), A.742(18), A.597(15) and A.466(XII), to provide basic guidance on the conduct of PSC inspections in support of the control provisions contained in relevant conventions and in the IMO Instruments Implementation Code (III Code) (resolution A.1070(28)). Procedures for PSC afford consistency in the conduct of these inspections, the identification of deficiencies of a ship, its equipment, or its crew, and the application of PSC procedures.

Following the continuous updating of the Procedures for PSC carried out by the Correspondence and Working Groups on Measures to Harmonized Port State Control (PSC) Activities and Procedures Worldwide, an Assembly resolution containing an updated version of the Procedures for PSC is adopted every two years. 

IMO Workshop for PSC MoU/Agreement Secretaries and Database Managers (PSCWS)

In order to further harmonize PSC activities, the Organization convenes, usually every two years, workshops for PSC MoU/Agreement Secretaries and Database Managers (PSC Workshops), in the form of open meetings. The seventh PSC Workshop was held from 24 to 26 October 2017 at IMO Headquarters. Workshops have been funded by under IMO Technical Cooperation Programme and, more recently by the Voyage Together Trust Fund and aiming at providing support to developing regional PSC regimes and establishing a platform for cooperation and sharing experience. PSCWS successfully encourage harmonization and coordination of PSC activities and development practical recommendations which have triggered further examination by the Organization's relevant Committees and Sub-Committees. The reports of the seven workshops are available on IMODOCS under "meeting documents/others/PSCWS"


Parties to a relevant convention, when they have exercised control giving rise to detention, should submit to the Organization reports in accordance with SOLAS 1974 regulation I/19, article 11 of MARPOL, or article X(3) of STCW 1978. On receiving a report on detention, the flag State should, as soon as possible, report the Organization of remedial action taken in respect of the detention 

The fulfilment of reporting requirements on PSC-related matters should be carried out electronically by PSC regimes, on behalf of the member countries and flag States through the GISIS module on PSC.

In the context of reporting on alleged deficiencies relating to the provisions of MARPOL, under the provisions of MARPOL article 6, summary reports and analysis of mandatory reports under MARPOL, including information collected under part 4 of MEPC.1/Circ.318 on the total number of ships boarded in 2018 by PSC, are circulated regularly (MEPC.1/Circ.888/Rev.12).

IMO’s response to COVID-19 Pandemic

In light of the COVID-19 pandemic, the Secretary-General convened two video meetings with all PSC regimes, held on 8 April 2020 and 17 June 2020, respectively. The first video meeting reviewed emergency response and measures taken by the Organization and recommended taking a “pragmatic, practical and flexible” approach to tackle these challenging times. A joint statement was issued in annex 1 of Circular Letter No.4204/Add.8. The second video meeting, in cooperation with the International Labour Organization and the International Association of Classification Societies, centred on the new IMO Guidance on surveys and renewals of certificates in the context of the COVID-19 pandemic. A press release was issued to reflect the outcome of the second video meeting with the PSC regimes.