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Everything you need to know about MMSI Numbers!

One of the most common questions we receive from customers at boat shows and via our website is about MMSI (Maritime Mobile Service Identity) numbers…what they are, how do they enter them and what happens if they get the process of entering them wrong. So, we thought we would put an article answering all the most common questions and few others that commonly come up.

So, let's get started with the most basic of all the questions.

What is an MMSI number?

Maritime Mobile Service Identity (MMSI) numbers are a series of nine digits used to uniquely identify a DSC radio or a group of DSC radios on a vessel. It is important to note that you don’t need to get an MMSI number if your handheld radio doesn’t have DSC.

The MMSI has a standard format (just like a telephone number), and it identifies the type of station, country of registration and vessel identity. In the UK MMSIs are assigned as a part of the ship's radio licensing procedure.

When sending a DSC message, the MMSI is automatically included, and you can address messages to specific vessels or groups using their MMSIs.

If you have a marine VHF radio installed on your boat, you will need a ship's radio licence from the OFCOM website. This is free of charge online, or you can do this via post, but there is a charge. You can obtain an application form for a ship's radio by applying via: ofcom.org.uk

If you have more than one DSC Radio on your vessel, they should each have the same MMSI number. However in the UK, any handheld DSC radio such as the IC-M94DE should be separately licensed and have its own MMSI number.

You can apply for a new MMSI when licensing your vessel with Ofcom. Once an MMSI is registered with Ofcom, the ITU and the MCA are informed so if searched on the ITU (International Telecommunications Union) MARS database (Maritime Access & retrieval system) your MMSI number will appear. You would need to input the ship's name and country and search for the owner's details. The ITU and MCA are informed to assist with SAR (Search and Rescue Operations).

An MMSI number can only be programmed correctly once, although you get two chances to validate the number. This leads us on to our second question.

I've tried to enter my MMSI number twice and now my radio won't accept another attempt. What do I do?

SOLAS requires that all Marine DSC radios are allowed only a single attempt to input an MMSI number. Your only solution now is to take the radio to a qualified Icom marine dealer who will be able to program the MMSI number for you.

I recently purchased a boat that includes an Icom radio. I have my own MMSI Number. Can I add it myself?
Unfortunately, not, the radio will need to go back to either your local Icom dealer or the Icom UK service department.

Why do Handheld DSC radios like the IC-M94DE have their own unique MMSI numbers?

Handheld DSC radios have their own, unique MMSI number format. Because handheld DSC's can be carried from ship to ship, they must not be programmed with a ship's MMSI*…think of the confusion for the rescue authorities if there was an incident.

Anyone who already holds a Ship Portable Radio Licence can go onto the OFCOM website and simply add VHF DSC handheld to their list of equipment. Again, licences are free of charge if issued online.

You mustn't put your ship's MMSI number into your Handheld DSC radio…this must be a unique handheld DSC MMSI number from OFCOM.

What should I do if I sell my DSC handheld radio?

You must surrender your Ship Portable Radio Licence. You cannot transfer the MMSI to the new owner until you do. If the new owner makes a DSC distress call, the MCA will always respond, but it may affect their efficiency if they don't have the correct contact details.

We hope this clears up a few of your questions about MMSI numbers and please note to use your marine radio, you will need an operator's licence. There are more details about how to get this in our article 'Getting Your Marine VHF Radio Licence'.