Idaho Code § 26-2124
A member may designate any person or persons to hold shares, deposits, and thrift club accounts with him in joint tenancy with the right of survivorship; but no joint tenant, unless a member in his own right, shall be permitted to vote, obtain loans, or hold office. Payment of part or all of such accounts to any of the joint tenants shall, to the extent of such payment, discharge the liability to all.
No credit union organized under the laws of this state shall be required to recognize the claim of any third party of any of the above such accounts or withhold payment of any such accounts to the depositor or to his order, unless and until the credit union is served with citation or other appropriate process issuing out of a court of competent jurisdiction in connection with a suit instituted by such third party for the purpose of recovering or establishing an interest in such above accounts.
Such above accounts issued by any credit union organized under the laws of this state in the name of two (2) or more persons or to two (2) or more persons or the survivor of either, may be withdrawn on the signature of either party of whom such accounts were issued, or in whose name such accounts were made, and no recovery shall be had against such credit union for amounts so paid. When such accounts are issued in the name of two (2) or more persons or in the name of their survivor, the survivor of either party shall have power to act in all matters relating to such accounts whether the other person or persons named in such accounts be living or dead. The repurchase or withdrawal value of such accounts issued in joint names and dividends thereon, or other rights relating thereto, may be paid or delivered, in whole or in part, to any such person who shall make requests therefor, whether the other person or persons be living or dead. The payment or delivery to any such person, on a receipt or acquittance signed by any such person, to whom any such payment or any such delivery of rights be made, shall be valid and sufficient release and discharge of any such credit union for the payment or delivery so made.
Idaho Code § 26-2124