Okla. Stat. tit. 12 § 937
In any civil action to enforce payment of or to collect upon a check, draft or similar bill of exchange drawn on a bank or otherwise, payment upon which said instrument has been refused because of insufficient funds or no account, the party prevailing on such cause of action shall be awarded a reasonable attorney's fee, such fee to be assessed by the court as costs against the losing party; provided, that said fee shall not be allowed unless the plaintiff offers proof during the trial of said action that prior to the filing of the petition in the action demand for payment of the check, draft or similar bill of exchange had been made upon the defendant by registered or certified mail not less than ten (10) days prior to the filing of such suit.
Okla. Stat. tit. 12, § 937