Okla. Stat. tit. 56, § 167.1

The Department of Human Services, with the written consent of the client, may request a copy of the financial records or any other records specified in said written consent from a financial institution or other agency regulated by federal or state law. The request shall be for the purpose of investigating the eligibility of the client for assistance or service from the Department. Said financial institution or agency shall furnish said records at no cost to the client or the Department. If the client refuses to sign said written consent, then the Department shall refuse the client assistance or service.