(a) Whenever any refunding bonds are purchased and cancelled under Section 280-20, the taxes thereafter to be extended for payment of the principal of and interest on the remainder of the issue shall be reduced in an amount equal to the principal of and the interest that would have thereafter accrued upon the refunding bonds cancelled. A resolution shall be adopted by the corporate authorities of the township finding these facts. A certified copy of this resolution shall be filed with the county clerk specified in Section 280-10, whereupon the county clerk shall reduce and extend the tax levies in accordance with the resolution.
     (b) Whenever refunding bonds are issued, proper reduction of taxes previously levied for the payment of the bonds refunded and next to be extended for collection shall be made by the county clerk upon receipt of a certificate signed by the supervisor or other corresponding officer of the township showing the bonds refunded and the tax to be abated.