Federal Communications Commission
News Media Information 202 / 418-0500
445 12th St., S.W.
Fax-On-Demand 202 / 418-2830
Washington, D.C. 20554
TTY 202 / 418-2555
Released: December 10, 2012
WIRELESS TELECOMMUNICATIONS BUREAU REMINDS MARINERS REGARDING
CORRECT USE OF MARITIME MOBILE SERVICE IDENTITY (MMSI) NUMBERS
By this Public Notice
, the Wireless Telecommunications Bureau reminds mariners and other
interested parties regarding the proper use of Maritime Mobile Service Identity (MMSI) numbers by
commercial and recreational vessels.1 An MMSI is a unique nine-digit number assigned to ship stations
that use Digital Selective Calling (DSC)2 or Automatic Identification System (AIS)3 equipment. As
required by treaty, the Commission assigns MMSIs in accordance with the International
Telecommunication Union (ITU) Radio Regulations and periodically notifies the ITU of assignments
made to vessels traveling or communicating internationally. Search and rescue authorities, including the
U.S. Coast Guard, may use the MMSI to find out background information about a vessel in distress (e.g.
owner's name, intended route, and other radio equipment on board) and to help determine whether the
alert is false. Thus, an accurate MMSI database can help to protect lives and property at sea by reducing
the time it takes to locate vessels in distress.
Obtaining an MMSI.
Vessel owners must obtain an MMSI prior to using a DSC radio,
shipborne universal AIS transponder, or INMARSAT ship earth station.4 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.
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
1 MMSI assignment and use by maritime support stations and by diver radios will be addressed in subsequent
2 DSC is an internationally approved system for automatically contacting vessels on MF, HF, and VHF frequencies.
It allows mariners to send an automatically formatted distress alert instantly to the Coast Guard or other rescue
authority anywhere in the world. DSC also allows mariners to initiate or receive distress, urgency, safety and
routine radiotelephone calls to or from any similarly equipped vessel or shore station, without requiring either party
to be near a radio loudspeaker. It allows users to “direct dial” and “ring” other maritime radio stations.
3 AIS is a maritime navigation safety communications system that provides vessel information, including the vessel's
identity, type, position, course, speed, navigational status and other safety-related information, automatically to
appropriately equipped shore stations, other ships, and aircraft.
47 C.F.R. § 80.103(b).
does not make international communications.5 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 radiobeacon (EPIRB), and any type of radar installation. Operators of
vessels that are licensed by rule can obtain MMSIs from these designated private registration agents:
BoatUS, Sea Tow International, Inc., Shine Micro, Inc., and Unites States Power Squadrons, Inc.6
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.
A fleet license allows several ship stations to be licensed under a single authorization. The FCC
does not assign MMSIs with fleet licenses. If a fleet-licensed vessel comes to require an MMSI, the
licensee must either license the ship station individually (if it requires a license from the FCC) or obtain
an MMSI from a private registration agent (if it can be licensed by rule).
The primary use of the contact information associated with an MMSI is to assist search and
rescue authorities in the event of an emergency, so it is important that the information be current.
Mariners are strongly urged to provide accurate information when first obtaining an MMSI and to
maintain the accuracy of that information by notifying the FCC (for individually licensed vessels) or the
private registration agent that issued the MMSI (for vessels licensed by rule) when their information
Using the correct MMSI.
Vessel owners and operators are responsible for ensuring that the
equipment on board a vessel is programmed with the correct MMSI. Several common situations have
resulted in vessels transmitting incorrect MMSIs.
Presently, licensed-by-rule vessels with an MMSI that later are licensed individually cannot use
the previously issued MMSI in the FCC licensing process.7 Nor can a vessel that formerly was registered
under a foreign flag use the foreign-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.
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
5 47 C.F.R. § 80.13(c).
6 Contact information for the four private registration agents can be found in Commission Announces Agreements
with Shine Micro, Inc., and United States Power Squadrons, Inc., and Termination of Agreement with MariTEL,
Inc., Regarding Assignment of Maritime Mobile Service Identities (MMSIs), Public Notice
, 22 FCC Rcd 7329
(WTB MD 2007), and at http://wireless.fcc.gov/services/index.htm?job=licensing&id=ship_stations
7 The Commission intends to reprogram its licensing system to accept the entry of a privately-issued MMSI and
process an individual ship station license application without automatically issuing a new MMSI number, in
conjunction with a future upgrade of the licensing system. See
National GMDSS Implementation Task Force, Order
, 24 FCC Rcd 3215, 32317 ¶ 9 (WTB MD 2009).
register the vessel with a private registration agent.8 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. A vessel that formerly was registered under a foreign flag, however, cannot use the foreign-
issued MMSI while it operates on a licensed-by-rule basis in the United States. Owners of such vessels
must obtain new privately-issued MMSIs.
After a vessel is sold or transferred, the seller/transferor must contact the FCC to cancel the
license (if the vessel was individually licensed) or contact its private registration agent to cancel the
MMSI (if it was licensed by rule). If the vessel was individually licensed, the buyer/transferee must file
an application for a new ship station license and, in connection with that application, may ask the FCC to
reassign the MMSI from the cancelled license to the new license. If the vessel was licensed by rule, the
buyer/transferee may ask the private registration agent for reassignment of the MMSI that had been
assigned to the seller/transferor.
Similarly, purchasers of used equipment are responsible for ensuring that the correct MMSI is
programmed into the device before it is used on board a different vessel.
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).9 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.
The assigned MMSI must be properly programmed into any device in which an MMSI is
required. Knowingly programming any such device with an inaccurate MMSI, causing such a device to
be programmed with an inaccurate MMSI, or falsifying MMSI registration information is prohibited.10
For further information, contact Ghassan Khalek of the Mobility Division, Wireless
Telecommunications Bureau, at (202) 418-2771, TTY (202) 418-7233, or firstname.lastname@example.org
8 The only exception is for MMSIs that end in three zeroes. MMSIs ending in trailing zeroes are not retained by
the vessel owner or operator, and will be assigned by the FCC to another ship station. The former licensee must
obtain a new MMSI from a private registration agent.
47 C.F.R. § 80.1061(e).
47 C.F.R. § 80.231(b).