IMO Number Question

Paul Beesley · Post by **Paul Beesley** » Tue Oct 19, 2021 10:53 am

The new Navibulgar ships, Kom (IMO 9905708) and Bogdan (IMO 9905710), both have IMO numbers starting with 99. The numbers issued are progressing upward with some speed. What is the IMO going to do once they reach the maximum 7 digit number, 9999999?

Mr Link · Post by **Mr Link** » Tue Oct 19, 2021 8:24 pm

FYI, the IMO number is really only a 6 digit number, with the seventh digit a "check" digit. You do some math to come up with the check digit to confirm the entire number is valid.

A comment at the bottom of this Wikipedia page implies that there are large swaths of IMO numbers that have not yet been used.

Wiki talk

(scroll to the very bottom)

I do know that MMSI numbers are re-used occasionally, so that may be an option as well, once a ship has been scrapped for a number of years.

Paul Beesley · Post by **Paul Beesley** » Wed Oct 20, 2021 9:47 am

Thank you.