MMSI Number Scheme
Posted: Sat Mar 18, 2017 12:44 pm
The Radio Technical Commission for Maritime (RTCM) has proposed changes to the FCC Rules Part 80 ("Stations in the Maritime Services") to add a section, 80.16, to contain details about "Assignment and use of numeric identities including maritime mobile service identities (MMSI's)."
Specific MMSI number formats are used for the many various types of MMSI users. The details of MMSI number assignment are given in ITU-R M.585-7. See:
https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.585-7-201503-I!!PDF-E.pdf
A brief summary of the categories of interest to recreational boaters follows. "MID" means "maritime identity digits" and indicates the country or region. For example, the United States is presently assigned use of the MID codes 338, 366, 367, 368, and 369. X or Y means any digit 0 to 9. "LBR" means licensed by rule.
SHIP STATION LICENSE: MIDXXXXX0, issued by the FCC for a fee.
COAST STATION: 00MIDXXXX, issued by the FCC for a fee.
LICENSED BY RULE (LBR): MIDXXXXXX, issued by an LBR agency; fee may be charged.
VHF HANDHELD LBR: 8MIDXXXXX; issued by an LBR agency; a fee may be charged; the radio must have DSC with GNSS.
VHF HANDHELD DIVER'S RADIO PERSONAL LICENSE: 8MIDXXXXX, issued by the FCC or USCG for a fee; the radio must have DSC with GNSS.
CRAFT ASSOCIATED WITH A PARENT SHIP: 98MIDXXXX, issued by FCC or FCC agent.
AIS ATON: 99MIDXXXX, no fee but an FCC station license is required
AIS SART: 970XXYYY, where XX is the manufacturer ID and YYYY is issued by the manufacturer.
AIS MOB: 972XXYYY (as above)
AIS EPIRB: 974XXYYY (as above)
AIS SEARCH AND RESUCE AIRCRAFT: 111MIDNXX; N indicates type of aircraft; issued by the USCG
The Radio Technical Commission for Maritime proposed changes can be seen in their entirety at
https://ecfsapi.fcc.gov/file/60001459667.pdf
For boaters who have an FCC-issued ship station license and MMSI, the number will always end in a zero. Boaters whose ship stations are licensed by rule will get an MMSI from an agency like BoatUS which can end in any digit except zero. At the moment the USA has been assigned five MID identities. This suggests that at this moment there are upper bounds to the number of FCC-issued MMSI identities; with only five digits available per MID, there appears to only be 99999 x 5 = 499,995 possible MMSI sequences. For licensed-by-rule boats, six digits are available but some of the available numbers (the ones ending in zero) are already taken by the FCC-licensed numbers. This suggests there are (999999 x 5) - 499,995 = 4,500,000 possible MMSI sequences available for that use.
Specific MMSI number formats are used for the many various types of MMSI users. The details of MMSI number assignment are given in ITU-R M.585-7. See:
https://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.585-7-201503-I!!PDF-E.pdf
A brief summary of the categories of interest to recreational boaters follows. "MID" means "maritime identity digits" and indicates the country or region. For example, the United States is presently assigned use of the MID codes 338, 366, 367, 368, and 369. X or Y means any digit 0 to 9. "LBR" means licensed by rule.
SHIP STATION LICENSE: MIDXXXXX0, issued by the FCC for a fee.
COAST STATION: 00MIDXXXX, issued by the FCC for a fee.
LICENSED BY RULE (LBR): MIDXXXXXX, issued by an LBR agency; fee may be charged.
VHF HANDHELD LBR: 8MIDXXXXX; issued by an LBR agency; a fee may be charged; the radio must have DSC with GNSS.
VHF HANDHELD DIVER'S RADIO PERSONAL LICENSE: 8MIDXXXXX, issued by the FCC or USCG for a fee; the radio must have DSC with GNSS.
CRAFT ASSOCIATED WITH A PARENT SHIP: 98MIDXXXX, issued by FCC or FCC agent.
AIS ATON: 99MIDXXXX, no fee but an FCC station license is required
AIS SART: 970XXYYY, where XX is the manufacturer ID and YYYY is issued by the manufacturer.
AIS MOB: 972XXYYY (as above)
AIS EPIRB: 974XXYYY (as above)
AIS SEARCH AND RESUCE AIRCRAFT: 111MIDNXX; N indicates type of aircraft; issued by the USCG
The Radio Technical Commission for Maritime proposed changes can be seen in their entirety at
https://ecfsapi.fcc.gov/file/60001459667.pdf
For boaters who have an FCC-issued ship station license and MMSI, the number will always end in a zero. Boaters whose ship stations are licensed by rule will get an MMSI from an agency like BoatUS which can end in any digit except zero. At the moment the USA has been assigned five MID identities. This suggests that at this moment there are upper bounds to the number of FCC-issued MMSI identities; with only five digits available per MID, there appears to only be 99999 x 5 = 499,995 possible MMSI sequences. For licensed-by-rule boats, six digits are available but some of the available numbers (the ones ending in zero) are already taken by the FCC-licensed numbers. This suggests there are (999999 x 5) - 499,995 = 4,500,000 possible MMSI sequences available for that use.