The International Maritime Organization (IMO) number is a unique identifier assigned to sea-going vessels to enhance maritime safety and security, as well as to facilitate the prevention of maritime fraud. It is a seven-digit number that is permanently linked to a ship’s hull, ensuring the vessel can be accurately tracked and identified throughout its entire life, regardless of changes in ownership, flag, or name.
The IMO number was introduced in 1987 through the adoption of the IMO Resolution A.600(15), which established the IMO Ship Identification Number Scheme. The system was later expanded to include fishing vessels and is now mandatory for all ships with a gross tonnage of 100 GT or more, as well as passenger ships, regardless of size. The IMO number is also recommended for smaller commercial vessels, but not for recreational boats or non-commercial ships.
The IMO number is assigned by IHS Markit (formerly Lloyd’s Register-Fairplay), which acts as the scheme’s administrator under the authorization of the IMO. The number is created using the following structure: the prefix “IMO” followed by a unique seven-digit number. For example, IMO 1234567.
The IMO number must be visibly displayed on the ship’s exterior (either the hull or superstructure) and should be marked in a clearly legible and permanent manner. It must also be permanently marked on the ship’s engine ,room bulkhead or another prominent location that is easily accessible for inspection. This is to ensure that the IMO number is visible and identifiable in case of incidents, accidents, or when authorities need to verify the vessel’s identity.
The purpose of displaying the IMO number in these prominent locations is to facilitate:
Easy identification: The IMO number enables authorities, port officials, and other relevant stakeholders to quickly and accurately identify a vessel, regardless of any changes in its ownership, name, or flag.
Safety and security: By having a unique identifier, the IMO number enhances safety and security by allowing authorities to track a vessel’s history, monitor compliance with international regulations, and detect potential maritime fraud.
Incident response: In case of emergencies, accidents, or maritime incidents, the IMO number can be used to gather vital information about the ship, its crew, and cargo, thereby enabling a swift and effective response.
Regulatory compliance: Displaying the IMO number on the ship’s exterior and engine room helps ensure that vessels are in compliance with international maritime regulations, such as the International Convention for the Safety of Life at Sea (SOLAS) and the International Ship and Port Facility Security (ISPS) Code.
Overall, the visible display of the IMO number on a ship’s exterior and engine room plays a crucial role in enhancing maritime safety, security, and regulatory compliance.