Hi Richard, due to legal requirements in North America and other countires the MMSI number can only be set up once for our AIS transponder. You cannot change the MMSI once it has been entered.

So please be certain you enter the MMSI carefully. Never use an unassigned or false MMSI (this is illegal in most countries).

You have to get your AIS transponder fully reprogrammed(not upgrading the firmware) in case you need to change it again in the future. Unfortunately, only our authorized distributors and we can do so. Thank you for understanding.

The following links may be helpful for you.

https://www.navcen.uscg.gov/?pageName=mtmmsi

https://www.boatus.com/magazine/2018/april/what-you-need-to-before-installing-ais.asp” class=”bbcode_url”>https://www.boatus.com/magazine/2018/april/what-you-need-to-before-installing-ais.asp