Whenever any county, road district, consolidated school district, rural school district, or other taxing districts controlled by the board of supervisors which has heretofore issued or shall hereafter issue bonds or other obligations of which principal and interest shall be payable at some bank or trust company, or at some office other than the county treasury, it shall be the duty of the clerk of the board of supervisors on the allowance of said board to issue a warrant against the proper fund for the amount of principal and interest due and to forward exchange to the paying agent. Said exchange shall be sufficient in amount to pay said principal and interest and a reasonable fee to said paying agent for handling same, said fee not to exceed one-half of one percent (½ of 1%) of the amount of coupons paid and one-eighth of one percent (⅛ of 1%) of the amount of bonds paid. Said exchange shall be forwarded in time to reach the paying agent at least five (5) days prior to the date on which said principal and interest shall become due, and the receipt of the paying agent for said remittance shall be sufficient voucher in the hands of said clerk for said remittance until the bonds or coupons shall have been paid and cancelled and returned to said clerk.