Okla. Stat. tit. 18, § 381.43
Any association or federal association may accept savings accounts or savings deposits in the name of any administrator, executor, conservator, guardian, trustee, or other fiduciary for a named beneficiary or beneficiaries. Any such fiduciary shall have power to vote as a member of a mutual association as if the membership were held absolutely, to open and to make additions to, and to withdraw such account or deposit in whole or in part. The withdrawal value of any such account or deposit, and earnings thereon, or other rights relating thereto may be paid or delivered, in whole or in part, to such fiduciary without regard to any notice to the contrary as long as such fiduciary is living. The payment or delivery to any such fiduciary or a receipt or acquittance signed by any such fiduciary to whom any such payment or any such delivery of rights is made shall be a valid and sufficient release and discharge of an association for the payment or delivery so made. Whenever an account or deposit shall be opened by any person who designates himself or another as trustee by written declaration of trust, which provides that the trust shall terminate upon his death, then, in the event of the death of the person so described as trustee, the withdrawal value of such account or deposit or any part thereof, together with the earnings thereon, may be paid to the person for whom the account was thus described to have been opened. The payment or delivery to any such beneficiary, beneficiaries or designated person for any such payment or delivery shall be a valid and sufficient release and discharge of an association for the payment or delivery so made.
Amended by Laws 1988, HB 1473, c. 65, § 24, emerg. eff. March 25, 1988.