Navy Federal UPDATE: WOW!

[KJinNC]

One option to join is "related to NFCU member." I have not tried this, but, the way it's worded indicates that you're not talking about verifying military membership at that point, just your relationship to a NFCU member.

OP: Was the person who sent you the code a close relative? If so, I'd call them and ask. If not, that's probably the reason for denial.

[Anonymous]

I didn't have a code before I called. 

I just called them and told them I wanted to join. They asked me if I was a military member or veteran. I told them no, but my father was -during the Vietnam Era.  

She didn't ask for any further information. 

ETA: I was the OP, but now that I reread this, I think you were referring to someone else