Okla. Stat. tit. 62, § 62-304.2: Assignment of salary or wage earnings

Except as otherwise provided by Section 165.3a of Title 40 of

the Oklahoma Statutes, assignment of salary or wage earnings in such

instance shall be by separate instrument, and by affidavit. Except

as otherwise provided by Section 165.3a of Title 40 of the Oklahoma

Statutes, it shall be unlawful to issue or authorize the issuance of

a municipal warrant for salary or wages to any person other than the

person earning the same, or to his or her assignee or the executor

or administrator of his or her estate or to any person entitled to

child support payments pursuant to an income assignment proceeding

or a garnishment proceeding. Except as provided by income

assignment procedures for the collection of child support, no

assignment of a part of salary or wages shall be made, and any

assignment of salary or wages before the same has been earned shall

be a nullity and shall avail the assignee nothing.