MMSI Number – What Is It and How to Get One?

If your boat gets lost in the sea, how do you think the coast guard can find you? They can find you through your MMSI number. What is the MMSI number, and how to get one?

MMSI stands for Maritime Mobile Service Identity. This identification number is issued to all new Ship Radio and Ship Portable Radio Licenses. You can get this number if you will first complete a VHF Radio course. This course will show you how to operate the radio of a vessel.

When your designated MMSI number is already installed in the DSC-VHF radio of your ship or boat, it can be used by the U.S. Coast Guard to search and rescue you if you are lost at sea. But your ship or boat must be within the jurisdiction of the Rescue 21 service areas.

If your boat or ship can navigate international waters, you should apply for your MMSI number with the Federal Communications Commission (FCC).

Read on to learn more about the MMSI number, how to get it, and how you can use it.

MMSI Number – What Is It and How to Get One?


The MMSI number is short for the “Maritime Mobile Service Identity” number. All new Ship Radio and Ship Portable Radio Licenses get this identification number. But before you can operate a ship’s radio, you have to finish a VHF Radio course. You can apply for a VHF radio license through an online portal.

If you already have your MMSI number in your boat or ship’s DSC-VHF radio, the U.S. Coast Guard can use it to search and rescue your boat should it get lost at sea, as long as it is within the Rescue 21 service areas. If your ship or boat can navigate international waters, you need to apply with the FCC for the appropriate MMSI registration.

Recreational boat owners who don’t have to have a marine radio and who only navigate in U.S. waters can get their MMSI numbers through an approved organization like the Shrine Micro (mainly for AIS), the Squadron, and the BOAT US 1-800-563-1536.

When you have completed the license application, it will take around 2 days for the FCC to issue your license. This license will include an MMSI number and a call sign for your boat.

MMSI Number Additional Details

If you conduct an MMSI number lookup, you will find that they have nine digits. The maritime DSC (digital service calling), AIS (automatic identification systems, and other equipment use these identification numbers to specifically identify a ship or a radio station on the coast.

If you get an MMSI number, it will function similarly to your mobile phone number. Your MMSI number is the unique calling number that you can use for AIS units or DSC radios.

The International Telecommunications Union in Geneva, Switzerland regulates and manages all MMSI numbers internationally, the same way they regulate radio call signs. The format of the MMSI number is documented in Article 19 of the ITU Radio Regulations and ITU-R Recommendation M.585-6, available from the ITU. 

If you already have a Ship Radio or Ship Portable Radio license, you have to amend this license and add related equipment. When you have completed the amendment, an MMSI number will be created and displayed on your license.

There is just one format for all MMSI numbers. It looks like this: MIDXXXXXX. The first three digits of an MMSI number refer to the MID or Maritime Identification Digits. These digits represent the nationality of the vessel. The digits following the MID digits are the ordinary numeral characters.

Do You Need an MMSI Number?

The ITU Radio Regulations, as well as the rules of the FCC, require watercraft owners to obtain their MMSI numbers before they use a Class A or Class B AIS, DSC radio, or an INMARSAT ship earth station.

You have to get an MMSI number before you can use an AIS transponder. Class B AIS transponders will not work if no MMSI number has been programmed into their systems.

Additionally, the rules of FCC require Class B AIS units to be programmed with the appropriate vessel information before shipping to addresses in the United States.

To use DSC-VHF radios in their full capacities, you have to program their unique MMSI numbers. All fixed mount VHF radio produced from 1999 forward has digital selective calling or DSC capability.

An MMSI number works like the phone number of your mobile. This enables boaters with DSC-VHF radios to make an emergency call that will automatically transmit vital information to all the other DSC-VHF radios within the vicinity of the caller. The call is straightforward to make because it is simply a touch-of-a-button process.

Who Issues MMSI Numbers?

mmsi number

The FCC is the government agency assigned to issue MMSI numbers. If you are planning to use your recreational marine vessel to travel outside of the domestic waters of the US, you need to obtain an MMSI number from the FCC. This includes traveling to the Bahamas, Mexico, and Canada.

The FCC is the agency that assigns MMSI numbers to recreational and commercial US-flagged vessels included in the Global Maritime Distress and Safety System or GMDSS. You have to get this number under the terms of the international treaty.

The FCC assigns the numbers according to the Radio Regulations of the ITU. This agency (FCC) also regularly updates the ITU of the assignments made to vessels traveling or communicating internationally.

If you are not planning to use your recreational boat outside of the domestic waters of the US, you don’t have to get an FCC-issued license. Instead, you can get your MMSI number by communicating with the United States Power Squadrons or BoatUS.

If the FCC still requires your recreational vessel to have a license after getting an MMSI number from the United Power Squadrons, or BoatUS or Sea Tow Service, you cannot use the MMSI number when applying for such license with the FCC.

The MMSI number issued to you by other authorized agencies is only valid for ship stations that do not require FCC-issued licenses. So, in such situations, you must have a new MMSI number issued by the FCC.

How to Get an MMSI Number

mmsi registration

To get the appropriate MMSI number for your boat or ship, you need to contact that specific agency in which your vessel is registered. You have two options to obtain this number.

Option 1

The first option will apply only to marine vessels that have the following characteristics:

  • Primarily used for recreation
  • Not required by law to have a radio
  • Do not conduct radio communication or visit with foreign ports

If your boat meets all of the above criteria, you can obtain your MMSI number from BoatUS. The FCC and the U.S. Coast Guard (USCG) have authorized this entity to issue MMSI numbers to such vessels.

Vessels that satisfy these three conditions are not required to get an FCC license. However, they may need to acquire an MMSI number if they want to use a VHF DSC radio, Class B AIS transponder, or EPIRB.

If your boat meets all these requirements, here is what you need to do to get an MMSI number:

  • You need to visit the BoatUS website.
  • Create an account
  • Fill-up the appropriate online form
  • Get your MMSI number

Or you can request a form that you can fill up. After filling up that form, send it through snail mail, or email, or fax to the physical address of BoatUS. You can get more detailed instructions on how to request an MMSI application form from the site.

There is no charge in requesting an MMSI number or MMSI registration. The whole process is absolutely free. However, if you plan to visit foreign ports or plan to communicate with a foreign port, you need to get your MMSI number from the FCC.

Again, MMSI number – what is it and how to get one? An MMSI or Maritime Mobile Service Identity refers to a nine-digit number capable of uniquely identifying ship stations, coast stations, group calls, ship, and coast earth stations. The Digital Selective Calling (DSC) radio and Automatic Identification System (AIS) unit transmit the MMSI numbers.

Option 2

If you have a US-flagged marine vessel and it does not satisfy all the conditions stated in option 1, you have to get your MMSI number from the FCC. You have to file a request for this number. But before requesting your MMSI number, your boat must already have an FCC Registration Number or FRN. If you don’t have one yet, you should register for an FRN.

Once you have obtained your FRN, here are the steps that you need to follow to get your MMSI number:

  • Visit the official website of FCC and log in to your account using your FCC Registration Number and your password. After logging in and you are presented with the Applications page, click “My Licenses.” This will start you on the following steps:
  • Click the “Apply for a New License” link. It is on the left hand side of the page.
  • Select “SA or SB –Ship” from the drop down list of the radio service. Please take note that ULS will choose the correct radio service code (SA or SB) depending on the answers you gave on the application. Once you’re done, click “Continue”. You will then encounter the pages below.

Assigned Call Sign Page

Answer “Yes” if your boat already has a four-letter call sign,

If your boat’s call sign has more than four letters or has any numbers, answer “No” to this question.

Compulsory Questions Page

Answer “Yes” to the question: “Are you required by law or treaty to carry a radio on your vessel?”

If you answer “No” to this question, the FCC will give you a Ship Recreational or Voluntarily Equipped (SA) license.

Ship License Type Page

Only choose “Portable” if you can defend the use of just one transmitter aboard two or more vessels. This will authorize the use of marine radio equipment on various vessels. This is not very common.

Only choose “Fleet” if you can confirm that no vessel in your fleet uses DSC or AIS equipment. If you choose “Fleet,” click on the “Attachments” link found at the top of the page. And then upload the certification.

Ship Radio Requirement Categories Page

This page will be displayed only if you answered “Yes” to the question: “Are you required by law or treaty to carry a radio on your vessel?”

Give a “Yes” answer to question ‘A’ if your vessel is 1,600 gross tons or more and its capacity is 12 passengers.

You should answer one of the questions on this page with a “Yes” to get a Ship Compulsory Equipped (SB) license. If you give a “No” answer to all the questions on this page, you will get a Ship Recreational or Voluntarily Equipped (SA) license.

After answering the previous questions, proceed to the following steps:

  • Review your application on the Summary Page and then click the “Continue to Certify” button to resume.
  • Sign your application on the Certification Page by typing in your name in the appropriate box and the click on the “Submit” button.
  • There will be some fees that you need to pay. The amount will be computed by the system.
  • Click the “Continue for Payment Options” button to choose your payment mode. All fees should be received by the FCC within 10 calendar days. Don’t forget to send in your payment.

Conclusion: MMSI Number

The MMSI number is an acronym for Maritime Mobile Service Identity number. It is an identification number that is issued to all new Ship Radio and Ship Portable Radio Licenses. If you don’t have this number yet, you can get it by completing a VHF radio course. This course aims to teach you how to operate a ship’s radio.

You have two options in getting your boat’s MMSI number. The first option is for recreational vessels, and the second option is for commercial vessels.