Idaho Code § 33-704

All school district warrants not presented for payment within two (2) years after being called shall be void and shall constitute no claim against the school district by which they were issued, and the treasurers of all school districts are hereby authorized to transfer any moneys set aside for the payment of such warrants to the general school fund of their districts at the expiration of such period, and no treasurer of any school district shall pay any warrant not presented within such two (2) year period. When any such transfer is made by the treasurer of any elementary district, a certificate of such transfer shall be filed with the county auditor.