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Author Topic:   MMSI: Where and How to Get One
jimh posted 11-27-2014 10:57 AM ET (US)   Profile for jimh   Send Email to jimh  
The Federal Communications Commission of the USA (FCC) recently issued a clarification on how boaters in the USA should obtain a maritime mobile service identity or MMSI. Unlike many federal documents, this one is quite clearly written. It explains the situation rather well. I will reproduce several sections of it verbatim:

Obtaining an MMSI. Vessel owners must obtain an MMSI prior to using a DSC radio, shipborne universal AIS transponder, or INMARSAT ship earth station. All equipment on the vessel, including handheld VHF-DSC radios, must use the same MMSI. How a vessel owner obtains an MMSI depends on whether the ship station requires a license from the Federal Communications Commission (FCC) or is instead licensed by rule.

It should be noted that this is not only a regulatory requirement, it is also a practical requirement. Digital selective calling (DSC) radios of the modern, Class-D category won't operate as DSC radios until you have initialized their DSC system with an MMSI, and they will nag you to program them with the MMSI until you do enter it into the equipment.

Next, the FCC defines the two categories of ship station license: licensed-by-rule and licensed individually by the FCC. The FCC explains how these categories apply.

A ship station is licensed by rule and does not need a separate license from the FCC if:

--the ship station is not subject to the radio equipment carriage requirements of any statute, treaty, or agreement to which the United States is signatory;

--the ship station does not travel to foreign ports; and,

--the ship station does not make international communications.

Note that you have to meet all three of these conditions to be eligible to be licensed by rule.

A ship station licensed by rule is authorized to transmit radio signals using a marine radio operating in the 156-162 MHz band, any type of AIS, any type of emergency position indicating radio beacon (EPIRB), and any type of radar installation. Operators of vessels that are licensed by rule can obtain MMSIs from these designated private registration agents:


--Sea Tow International, Inc.,

--Shine Micro, Inc., and

--United States Power Squadrons, Inc.

For most recreational boaters that are not boating in border regions, their boat transmitter will be licensed-by-rule and they will get an MMSI from a private registration agent, one of the four listed above. If you are a boater in a border region and anticipate going into foreign water and communicating with foreign shore stations, for example, boating to Canada and calling a Canadian marina on the radio, your boat transmitter cannot be licensed by rule. You must get an individual license from the FCC.

Ship stations that are not licensed by rule must be licensed by the FCC. The FCC assigns MMSIs to vessels with individual licenses through the ship station licensing process. An MMSI is assigned as part of the grant of an application for a new license.

Now comes the confusing part. If you already had an MMSI from a private issuing agent, and you decide to get an FCC license, what should you do? The FCC says:

Presently, licensed-by-rule vessels with an MMSI that later are licensed individually cannot use the previously issued MMSI in the FCC licensing process.... Instead, when the new license is granted the FCC will assign the ship station a new MMSI. This MMSI must then be programmed into the vessel’s equipment in place of the previous MMSI. In addition, the licensee must have its private registration agent cancel the privately-issued MMSI.

In 2007 a boating industry group, the National GMDSS Implementation Task Force, petitioned the FCC to change this rule and process, and asked the FCC to permit the MMSI from a private issuing agent to be carried with the boat if the boater obtained an FCC ship station license. The petition pointed out the burden on the boater of having to reprogram all DSC devices with a new MMSI. Hundred of public comments were filed that supported the request for change. The FCC agreed that the petition had merit, but in 2009 it denied the request. The FCC cited the burden of the cost to alter their licensing system to make only this single change, and said that in the future, when considering modification to their licensing system, they would also consider adding this change. (See for details.)

Five years later in 2014, the FCC still has not changed its licensing system, and boaters are still stuck with having to change their boat's MMSI number when moving to an FCC issued MMSI from a privately issued MMSI. The FCC also explains:

On the other hand, a licensee that cancels a ship station license or allows it to expire (because the vessel no longer requires an individual license) generally may retain the FCC-issued MMSI and use it to register the vessel with a private registration agent. The vessel must then be registered with a private registration agent because its emergency contact information will be purged from the FCC’s licensing database.

What is described here is a situation in which the licensing process of the private issuing agents is apparently more sophisticated than the licensing process of the FCC. The private agents can accept a new registration from a boater who has an FCC-issued MMSI and let the boat retain that MMSI number, but the FCC cannot accept the MMSI from the private agents. I guess this is a case of smaller agencies being more nimble than large agencies.

The FCC also makes an important distinction about the programming of emergency beacon device as distinct from other DSC devices that use an MMSI:

The vessel MMSI should not be programmed into a 406 MHz EPIRB. FCC rules require that 406 MHz EPIRBs on United States vessels be encoded and registered with the hexadecimal identification code assigned by the National Oceanic and Atmospheric Administration (NOAA). Users should ensure that the coding marked on the EPIRB is correct and matches data registered with NOAA, and that contact information registered with NOAA is accurate and current.

For the entire public announcement in the most easily read form, obtain a copy from

There are other on-line versions of this document, but their presentation is not very clear. The PDF document linked above it much easier to read. It is also fully annotated with several footnotes and cites many references, which I have omitted in my quoted material above.

jimh posted 11-27-2014 12:10 PM ET (US)     Profile for jimh  Send Email to jimh     
The burden on boater's today when changing the MMSI in their equipment is actually much greater than it was seven years ago in 2007 when the FCC was petitioned to change their rules and procedures. In c.2007 there were many DSC devices which permitted the operator to enter the MMSI into the equipment more than once. This means that if the MMSI of a boat were changed, the owner could change the MMSI in the DSC equipment himself, assuming that he had not already used up all the opportunities provided by the equipment to change the MMSI. Typically DSC equipment permitted two entries of MMSI by the user. This suggests that the MMSI could be changed at least once by the owner for many device from that era.

At present day, DSC radios and other DSC equipment typically only permit the entry of the MMSI once, and changing the MMSI requires that the radio be sent to the factory for service (or in some cases a factory authorized service agency can perform an MMSI reset in the field). And in the case of AIS transponders, the user is not permitted at any time to enter the MMSI into the equipment, so all AIS transponders would require return to the factory or a service center for change of the MMSI.

I do not see much real value in the requirement that a DSC radio must only permit entry of the MMSI one time before needing return to the factory. I suppose this requirement was made with the notion of preventing boaters from changing the MMSI of their DSC radios in a mischievous fashion. Considering that a new Class-D DSC radio today costs only about $150 (or less), there is really not much of a burden for someone who wants to create mischief with changing MMSI identifies in a radio; they can just buy a new radio and program it with any MMSI they like. If some group or organization wants to create confusion with MMSI numbers, it will only cost them a pittance per radio to make their mischief.

jimh posted 11-27-2014 12:28 PM ET (US)     Profile for jimh  Send Email to jimh     
The administration of ship station licenses by the FCC is also strange, in my opinion. The FCC approaches the licensing as if the ship itself were an entity, that is, the MMSI belongs to the ship not to the ship owner. The FCC says that if I sell my boat, the MMSI is supposed to be passed along with the boat to its new owner. If I get a new boat, I am supposed to get a new MMSI for it.

I suppose this seems reasonable if you consider that the goal is to conserve the total number of MMSI identities in use by tying the MMSI to the boat. If the MMSI were tied to a boat owner, there could be a lot of legacy MMSI numbers being held by people who no longer own a boat. The total number of those MMSI identities might eventually become so large that they took up a lot of the available numbering space for the MMSI system. And the numbering space is not infinite. Even thought MMSI identities are nine-digits, they involve a three-digit embedded identity for the issuing agency, leaving only six digits available, that is 999,999 identifies, for the agency to issue. But there are further constraints on the numbers regarding requirements for a trailing zero. This means in some cases only five digits for the identity, or 99,999 choices.

The inability of the FCC to accept previously-issued MMSI numbers means that many boaters now have two MMSI identifies registered for one boat, which means consuming more MMSI number space, i.e., about double the actual number of boats.

Hoosier posted 11-27-2014 08:57 PM ET (US)     Profile for Hoosier  Send Email to Hoosier     
This is a classic example of "I'm from the Government and I know what's best for you'. It gets even more interesting in the case of a DSC handheld radio. I have two boats, one [with an MMSI from a private registration agency] and the other [with an MMSI issued by the FCC], but I take the HH radio with me on each boat. I can't change the MMSI number to match the boat I'm using the radio on. So if I'm out on my boat [with an MMSI from a private registration agency] and send out a DSC distress on the HH Radio the [responders who can look up information about the MMSI in real time to get the boat data] are going to be looking for me based on the data of the other boat. Not a very smart system--at least they're both Whalers.;-)
jimh posted 11-28-2014 05:58 AM ET (US)     Profile for jimh  Send Email to jimh     
An auxiliary radio transmitter on a boat--like a hand held portable radio--that has digital selective calling (DSC) features should have an MMSI that is the same as the boat. This follows the general concept that the MMSI is associated with a boat, not with an individual person who happens to own the boat.

I don't think there is a conflict here that is due to anything that is a function of which agency issued the MMSI. You could have two boats, with each having its own MMSI, and both MMSI numbers issued by the same agency. You'd have the same problem with carrying the same portable radio on the two boats. The radio MMSI can only match one boat.

If you were to send a DSC distress alert from your boat with the portable radio that had a mis-matched MMSI, the only responders that would know there was a difference are those who can access the MMSI look-up database. A good samaritan boater coming to your rescue won't know what your name is or what kind of boat to look for. They'll only get your position coordinates and the distress alert. Agencies like the Coast Guard of the USA might be able to perform a look-up on the MMSI, and they might retrieve your contact information and boat description. I think they might attempt to contact you via the contact information in the registration as a means of verifying if the distress alert is legitimate.

jimh posted 11-28-2014 08:14 AM ET (US)     Profile for jimh  Send Email to jimh     
Note that the policy of identification of emergency position-indicating radio beacon (EPIRB) devices is contrary to that of MMSI and boats. The FCC requires the registration of the EPIRB without involving the boat MMSI identity. The EPIRB device comes with its own embedded identity created by the manufacturer. It is the EPIRB device itself that has an identity.

The owner of the device then registers himself as having possession of that EPIRB device. When the EPIRB device is activated, it identifies itself--the EPIRB device itself--and then the owner is identified by association with the device by looking up the data in a table. The identification is a 15-character hexadecimal number. This allows for a total number of identities to be perhaps as high as 1,152,921,504,606,846,975--an enormously large number, many time larger than the number of people on the planet.

There is also a very significant difference between registering a 406-MHz EPIRB and registering for a MMSI: there is NO CHARGE to register an EPIRB with the official government agency data base maintained by NOAA. This is in contrast with the government policy for getting an MMSI from the official government registrar, the FCC. You have to pay $160 to register, and then renew every ten years.

There is also quite a difference in the system of communication used to relay the distress alert. With EPIRB 406-MHz, your distress alert transmission must be received by a satellite, which will then relay the message by some means, typically satellite to satellite, then satellite to earth station, then earth station to computer network. Then the system operators have to maintain a database with potentially many, many billions of identities, search that database, and find the owner of the beacon.

With a DSC distress alert sent on VHF radio, the signal goes from your boat all boats and shore stations in range. It has to be much cheaper to maintain a system of shore stations than to maintain a system or orbiting satellites, earth stations, and data networks. Yet EPIRB registration is at no cost, while MMSI registration is $160.

Both systems, EPIRB and DSC radios, are part of the Global Maritime Distress Safety System (GMDSS). The GMDSS is "an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft."

Why do I have to pay $160 to get an MMSI? Why do I have to change the MMSI if I get a new boat? Why to I have to pay a $60 (or higher) fee to make any modification to the MMSI data (such as changing address)?

In contrast, an EPIRB is registered for free. You can update the data for free. There is no charge for renewal of the registration. You can carry the EPIRB with you anywhere, land or sea. The EPIRB user never pays for any of these administrative costs; he just pays once, when he buys the EPIRB.

jimh posted 11-29-2014 08:47 AM ET (US)     Profile for jimh  Send Email to jimh     
[I separated the topic of AIS SART devices to its own thread.]
jimh posted 12-07-2014 09:42 AM ET (US)     Profile for jimh  Send Email to jimh     
The proper MMSI to be used with a handheld VHF Marine Band radio with DSC features is discussed at the U.S. Coast Guard website NavCenter. See

There you will find the following interesting information:

Obtaining MMSIs for DSC-equipped VHF Handhelds

A handheld VHF transceiver with DSC and an integral global navigation satellite system (e.g. GPS) not intended for dedicated use on a particular ship (e.g. a diver’s radio) should be assigned a unique 9-digit number in the format 81M2I3D4X5X6X7X8X9. While currently means do not exist within the U.S. to assign such identities, the Coast Guard has been in discussions with the Federal communications Commission and others on implementing them.

In the interim, VHF handhelds used in the United States should use the MMSI assigned to the ship to which the handheld is primarily associated, even if another radio on that ship uses the same MMSI. Non-commercial users of VHF handhelds not primarily associated with any single ship may use an MMSI provided by an organization such as BOAT US, SEA TOW and U.S. Power Squadron (see above). VHF handhelds should not be used ashore absent FCC or NTIA authorization allowing such use.

Executive summary: there are regulations in existence for a handheld radio to have its own MMSI, but there are no means to implement this in the USA. If you use a handheld with more than one boat, get the handheld its own MMSI from BoatUS or other private issuing agencies.

jimh posted 07-22-2015 01:14 PM ET (US)     Profile for jimh  Send Email to jimh     

Several private MMSI-issuing agencies in the USA have recently announced changes in their policies regarding access to registration, management of accounts, and fees for service.

Beginning July 24, 2015, the private MMSI-issuing agency BoatUS has indicated that it will begin to charge $20 for the issuing and registration of an MMSI for non-members of BoatUS. For BoatUS members there will be no fee for registration and issuing of an MMSI:

BoatUS provides MMSI free to Members. As of July 24th, non-Members may obtain an MMSI for a fee of $20 with a complimentary one-year membership included.

The private MMSI-issuing agency SeaTow presently has a message on their website announcing that access to MMSI account management and account registration in not available, and they seem to imply they are discontinuing their MMSI-registration service:

MMSI account management/registration is currently unavailable.

Existing accounts registered through Sea Tow may still be updated. Please email us at to update your existing account. To register for a new MMSI, visit the United States Power Squadron...

SeaTow's announcement includes hypertext linking to the United States Power Squadron.

United States Power Squadron
The private MMSI-issuing agency United States Power Squadron appears to be continuing to offer registration and issuing of MMSI to boaters at no charge:

This web site will be your portal to obtaining a MMSI for your vessel at no charge.

Shine Micro
The private MMSI-issuing agency Shine Micro offers MMSI registration and issuing for its customers that have purchased an MMSI certificate for $25 from Shine Micro via an on-line shopping cart sales system:

Code: NUM-MMSI-001
Price: $25.00 USD

After purchase, customers will be prompted to use their order confirmation number to proceed through online assignment and registration.


The United States Power Squadron appears to be the only private MMSI-issuing agency that continues to offer the registration and issuing of MMSI at no cost to any boater. Note that obtaining an MMSI from the FCC can be done at no additional cost when applying for an FCC Ship Station license.

jimh posted 08-01-2015 08:42 PM ET (US)     Profile for jimh  Send Email to jimh     
It appears to me that perhaps the BoatUS organization is having some trouble implementing their pay-to-play MMSI web-based registration. I say this because every time they announce a sunset date for the free registration, an extension to about one week into the future is announced when the sunset date is reached. At this writing, the sunset date is now set to be August 20, 2015.
jimh posted 08-23-2015 10:13 AM ET (US)     Profile for jimh  Send Email to jimh     
BoatUS seems to be approaching asymptotically the time when it will transition to a user fee for non-members who want to obtain an MMSI from their registration server. With the sunset date of August 20, 2015 now in the past, their website presently warns that the implementation of a fee will begin on September 1, 2015.
jimh posted 09-12-2015 12:38 PM ET (US)     Profile for jimh  Send Email to jimh     
From what I can tell from the BoatUS website, it appears they have dropped their notice of plans to charge a fee to non-members for registration of an maritime mobile service identity (MMSI). They also seem to have revamped their on-line registration, and improved the data entry and guidance. But I couldn't find any evidence that they were charging a fee. Perhaps that comes into play at the very end of the registration process. If anyone actually registers a new MMSI, please let me know if you were asked for payment at some point in the process if you are not already a BoatUS member.

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