Ref number

Got a question about the Mariner Reference Number, googled it and not much there except it’s a seven digit number, cool, my reference number is low 6 digits, never really mattered to me until my number came into question, CG gave me my number, been using it for many years, Saude

I think your answer is found 46 CFR § 10.207 Identification number.

For recordkeeping purposes only, a mariner’s official MMC identification number is the individual’s social security number. However, a unique serial number, called the mariner reference number, and not the social security number, will appear on the credential.

[USCG–2006–24371, 74 FR 11216, Mar. 16, 2009, as amended by USCG–2004–17914, 78 FR 77888, Dec. 24, 2013]