USCG advises what to do when selling or disposing of your radio or radio-equipped vessel

The United States Coast Guard has published a marine safety information bulletin advising what to do when selling or disposing of radio or radio-equipped vessel.

Maritime Mobile Service Identities (MMSIs) play a crucial role in maritime communications, enabling digital selective calling (DSC) and automatic identification systems (AIS) to uniquely identify ships and coast radio stations.

These nine-digit numbers are essential for effective search and rescue operations, allowing Coast Guard watchstanders and search authorities to swiftly identify vessels or individuals in distress and provide timely assistance, potentially saving lives and protecting property at sea.

Properly managing MMSIs is particularly important when selling or disposing of a radio or a radio-equipped vessel.

When the ownership of such equipment changes hands, it is essential to take the necessary steps to maintain the accuracy and validity of MMSI registrations.

Neglecting to do so can lead to serious consequences, as outdated or invalid MMSI registrations may hamper the differentiation between real distress situations and inadvertent alerts, delaying response efforts during emergencies.

To ensure the correct configuration of MMSIs, individuals must adhere to the following guidelines:

  1. Selling Your Vessel: If you decide to sell your radio-equipped vessel, it is critical to either delete your own-ship MMSI and cancel the registration or arrange for the transfer of the MMSI registration to the new owner before completing the sale. In cases where the vessel has multiple MMSI-equipped devices, transferring the registration may not be possible for a single radio, necessitating the deletion of its MMSI.
  2. Retaining Equipment: If you retain an AIS or DSC-equipped radio after selling your vessel, it is vital to have the MMSI deleted from the equipment. If you intend to use the radio with another vessel, you must obtain a new MMSI and enter it accordingly.
  3. Purchasing Used Equipment: For individuals purchasing a used VHF radio equipped with DSC and an AIS, ensuring that the MMSI registration is transferred from the original owner is essential. If this is not possible, contacting the manufacturer to have the original own-ship MMSI deleted is necessary before using the radio.
  4. Deleting Own-Ship MMSI: Deleting the own-ship MMSI requires adherence to specific regulations. It is advisable to contact the radio manufacturer or its representative to determine the proper deletion process for the specific model. The method may vary from entering a provided code to requiring the assistance of a dealer or the manufacturer for more complex procedures. This step is particularly crucial for individuals purchasing DSC-equipped radios or Class A or Class B AIS units to ensure proper MMSI management.
  5. Cancelling and Transferring MMSI Registration: Various organizations, such as the FCC, BOAT US, U.S. Power Squadron, Shine Micro, and SEA TOW, offer online services to facilitate the cancellation or transfer of MMSI registrations. Coordination between the seller and buyer is necessary to effectuate the transfer successfully. If uncertain about the organization responsible for the MMSI registration, individuals can easily find out through available resources.

By diligently following these steps and maintaining accurate MMSI registrations, individuals contribute significantly to the safety and efficiency of maritime operations.

Proper MMSI management not only aids search and rescue authorities in responding promptly to distress calls but also enhances overall maritime safety, ensuring smoother communications and reducing response time during emergencies.

This bulletin (MSIB 09-23) was issued on 21 June 2023.


For more information, please see the documents below (available only to subscribers):


Maritime Mobile Service Identities (MMSIs): What to do when Selling or Disposing of your Radio or Radio-equipped Vessel