<P> The International Maritime Organization (IMO) number is a unique reference for ships and for registered ship owners and management companies . IMO numbers were introduced under the SOLAS Convention to improve maritime safety and security and to reduce maritime fraud . For ships, the IMO number remains linked to the hull for its lifetime, regardless of a change in name, flag, or owner . </P> <P> The ship number consists of the three letters "IMO" followed by a unique seven - digit number assigned to sea - going merchant ships under the International Convention for the Safety of Life at Sea (SOLAS). </P>

What is an imo number for a vessel