You can obtain a MMSI number from various organizations, such as the Federal Communications Commission (FCC), Boat US, Sea Tow, the Power Squadron, and Shine Micro. The registration process may vary depending on the organization, but generally you need to provide some basic information about your vessel, such as its name, type, size, colour, owner and contact details. You also need to specify the type of radio equipment you have on board and the areas where you operate.