The Inmarsat Mobile Number (IMN) is the subscriber's number, which is used for calling a terminal. It performs exactly the same function as a telephone number. To obtain an IMN and activate an Inmarsat station it is necessary to contact the Point of Service Activation (PSA).

The PSA is an entity that has taken out a contract with Inmarsat for the activation and maintenance of records and accounts of Inmarsat terminals. A PSA in some cases can be a one-stop shop for service activation, terminal equipment provision and customer support. The PSA may not necessarily operate within the country where the vessel is registered, but the PSA must abide by the appropriate national regulatory framework. The Fleet terminal must meet all national licensing requirements. The PSA is responsible for the enforcement of any national licensing requirements.

Instant recognition by the SES is possible, given the distinct identification number system for each satellite system. For systems B,C and M it includes MID after the initial digit followed by any 5 digits (usually combined with MMSI). The fleet system indentification begins with 76 or 60 followed by any 7 digits.

Some examples:
  • Inmarsat-B Ships: COSTA CLASSICA 324798181; MAERSK ABERDEEN 347700140
  • Inmarsat-C Ships: SEA EMPRESS 431252310; MAERSK ABERDEEN 447701033
  • Inmarsat-Fleet 77 Ships: SEA EMPEROR 600935012, 764848792; LUCIJA 600958665, 764881430
All kinds of ship identifications are available on the ITU web site ( in the MARS (Maritime mobile Access and Retrieval System) database. Details for each ship with a registered radio station are available too. The database includes data about ship call signs, MMSIs, Inmarsat numbers and much more.
Last modified: Saturday, 25 April 2020, 7:50 PM