Okla. Stat. tit. 11 § 36-406
Upon the expiration of thirty (30) days after the passage of the assessing ordinance, the governing body may provide by resolution for the issuance of negotiable interest coupon bonds. The bonds shall be designated Local Improvement Bonds and shall be of such denominations and in such form as the governing body shall determine. The bonds shall bear the date of thirty (30) days after the publication of the assessing ordinance and shall bear interest at the rate of seven percent (7%) per annum until paid, and ten percent (10%) per annum, from maturity. The bonds may be registered in the name of the holder thereof and shall be payable at the office of the municipal treasurer or at the fiscal agency of the State of Oklahoma. The interest thereon shall be payable annually on the first day of September of each year. Upon the issuance of the bonds, they shall be delivered to the municipal treasurer and shall be sold at not less than par. If the governing body deems it most advantageous to the municipality, the bonds may be used for the payment of the cost of acquiring the real estate necessary for the improvement. The bonds shall be paid from the accumulation of assessments, interest and penalty, levied against the several lots and tracts of land described in the assessing ordinance. The accumulations shall be retained in a separate, special fund used for the purpose of paying the bonds and interest thereon, and for no other purpose whatsoever. Any surplus remaining in the fund, after the payment of all bonds and the interest thereon, shall become the property of the municipality. In no event shall the municipality be liable for the payment of the bonds.
Okla. Stat. tit. 11, § 36-406