Iowa Admin. Code r. 261-116.8
A certificate and related tax credit issued pursuant to Iowa Code section 15E52. as amended by 2013 Iowa Acts, House File 615, shall be deemed a vested right of the original holder or any transferee thereof, and the state shall not cause either to be redeemed in such a way that amends or rescinds the certificate or that curtails, limits, or withdraws the related tax credit, except as otherwise provided in rules 261-1166. (15E) and 261-1167. (15E) or upon consent of the proper holder. A certificate issued pursuant to this rule cannot pledge the credit of the state, and any such certificate so pledged to secure the debt of the original holder or a transferee shall not constitute a contract binding the state. A taxpayer does not obtain a vested right in such a tax credit until a certificate has been issued by the authority.
Iowa Admin. Code r. 261-116.8