Okla. Stat. tit. 18, § 18-381.45: Power of attorney - Revocation

Any association or federal association may continue to recognize

the authority of an attorney-in-fact authorized in writing to manage

or to make withdrawals either in whole or in part from a deposit

account, whether of a minor or adult, until it receives written

notice or is on actual notice of the revocation of such authority.

For the purposes of this section, written notice of the death or

adjudication of incompetency of such deposit account holder shall

constitute written notice of revocation of the authority of the

attorney.