Okla. Stat. tit. 56, § 240.4

A report of the payments made by the obligor or payor or of AFDC payments made to a person entitled to support which is prepared by the Division, the District Office, or by public agencies in other states with a certification of authenticity executed by the Division, the District Office, or a public agency in another state is admissible into evidence in district court or in an administrative court proceeding as self-authenticated.