My husband has a child from his previous marriage. He has joing custody. He lives with his mother and myhusband pays child support. The child is 17. He told us the other day that he wants to drop out of High School and joing the Army. I want to know 1) if he can do this at the age of 17 - does he only need one parent to consent or both and 2) Will the Army take a 17 year old without a High School Diploma?
I can't seem to find anything on the Army webpage regarding these two issues.

Have to have a GED or diploma to join the military. Historically, army required father's signature. For a minor today, would require signature of both parents if there is joint LEGAL custody - child support payments mean absolutely nothing.

Since they have "JOINT" custody ( I think that was what you tried to say) they would need both parents to sign.

But they won't take him at this point, without a high school degree or a GED.
So let dad take him down to talk to a recruiter and find out the facts first hand