Okla. Stat. tit. 19, § 19-691: Refund or payment only on voucher of county clerk

All money collected through error by the county treasurer, and

all other funds of whatsoever kind that shall come into his

possession by virtue of office, except such as is required to be

disbursed on warrant, bond, interest, coupon or depository voucher,

shall be refunded or paid out as the case may be, only on voucher

issued by the county clerk. No county treasurer shall, after having

filed with the county clerk any report of collections, make any

refund of any part thereof, except in the manner as herein provided.