Legal Question in Wills and Trusts in Illinois

Generally speaking, the surviving joint tenant becomes the sole owner. The decedent's estate can in certain circumstances argue that the joint tenancy account was just a convenience account without the intent to make a gift, but that requires significant proof and generally court action.

It depends on the understanding under which the account was established. If the account were truly joint, with each joint tenant an owner of the account, each authorized to make withdrawals, the surviving joint tenant is the sole owner on the death of the other. However, there are different forms of joint ownership, and once the bank comes to know that one of the joint tenants is deceased, it may be difficult to make withdrawals.