205 ILCS 305/41: Joint accounts.

Shares shall be issued in the name of the owner and may be issued in the name of 2 or more persons in joint tenancy, or in survivorship, in which case payment may be made, in whole or in part, to any of the named persons whether the others are living or dead, if an agreement permitting such payment was signed and dated by all persons when the shares were issued or thereafter. Only one of the persons must have the common bond of association, community or occupation specified in this Act and only that person may vote in a meeting of the members, obtain loans, hold office or be required to pay an entrance fee.