We get this question all the time, so we decided to do a blog post for our inquiring clients.

Although VHF radios are not required on recreational boats under 65.5 feet long, you should have one for the obvious safety reasons. It allows instant communication between your boat and other boats, marinas, bridges, and the United States Coast Guard (USCG) in case you run into trouble on the water.  So, you need one. There are also requirements that you need to have when you have a VHF. One is the Maritime Mobile Service Identity, or MMSI which is a 9-digit number used to identify a ship via radio.

If you are going to be traveling to a foreign port you’re required by law to have a radio on your vessel and you need an MMSI number. Also, the MMSI number is required for all AIS transponders to transmit your identity over the air.  The digital DSC Emergency Alert will not function without the MMSI number.  If you are a US documented or registered vessel and are required to have MMSI # then you are also required to have an FCC Ship Station License & Restricted Radio Operators (another post).

There are approved boat owners’ organization that assign MMSI numbers.  The FCC and US Coast Guard authorize organizations to assign domestic MMSI numbers. The application process is very simple. You receive your MMSI number immediately so it’s not a hassle.

As of 2019, authorized organizations include:

Boat US: https://www.boatus.com/MMSI/MMSI/Home

US Power Squadron: http://www.usps.org/php/mmsi_new

You may have to join the boating organization you’re going to use before it will assign you an MMSI. Others, such as Boat US, assign MMSI numbers to non-members for a fee. However, if you’re a member of the organization, you can get your MMSI number for free, as well as having access to other organization resources. For instance, the membership may include tow service or other assistance if you run into problems.

Once you log on the chosen site, you are led through the process. It’s very easy. You need to have your boat information. Immediately after you submit your application, a confirmation page will appear with your new MMSI number. Usually, you will receive this information through a confirmation email as well. Print at least 2 copies, one for your boat and one for your home records of the MMSI number. Now you’re ready to program the MMSi into your radio.

Check your VHF’s manual. There should be programming instructions, which vary by radio, so check your product’s user manual. Read the directions carefully and enter your MMSI number precisely. Most radios can only be programmed with an MMSI number once, so it you make a mistake, you may have to send your radio back to the manufacturer to get it cleared!


Good luck and let us know how it goes!