There are two basic different forms of joint bank accounts.  When looking at opening a shared/joint account it is important to discuss with the bank and your lawyer to see what is the best account to fit your needs and goals.  One is used to simply allow someone signing authority on another person’s bank account, but has no other legal effect.  The other, or so called “true” joint account, includes a right of survivorship, which means that whomever lives longest gets all the money in the account notwithstanding who put it there or who earned it.