MMSI, Radio Licensing & Call Signs Explained

Your vessel needs proper radio licensing to communicate safely at sea.

MMSI (Maritime Mobile Service Identity)

A unique 9-digit number for your vessel’s radios, AIS, GMDSS equipment.

Call Sign

Your vessel’s international radio identifier.

Radio Licence

Required for:

  • VHF
  • MF/HF radios
  • EPIRBs
  • AIS
  • Satellite equipment

Many flag states issue radio licences automatically with registration when handled through PMR.