https://www.taxtmi.com/caselaws?id=128697 A valid sales tax exemption cannot be converted into a retrospective tax liability merely because a later amending Act omits the exemption entry with retrospective effect. Where the exemption was in force throughout the relevant period, a deeming provision alone does not authorise past levy in the absence of an express legislative mandate. The operative principle is that lawful exemption during the taxable period defeats retrospective assessment unless the statute clearly creates such liability. en-us Fri, 15 Mar 1963 00:00:00 +0530 Wed, 10 Apr 2013 12:41:27 +0530 TaxTMI RSS Generator https://www.taxtmi.com/caselaws?id=128697 A valid sales tax exemption cannot be converted into a retrospective tax liability merely because a later amending Act omits the exemption entry with retrospective effect. Where the exemption was in force throughout the relevant period, a deeming provision alone does not authorise past levy in the absence of an express legislative mandate. The operative principle is that lawful exemption during the taxable period defeats retrospective assessment unless the statute clearly creates such liability. Case-Laws VAT and Sales Tax Fri, 15 Mar 1963 00:00:00 +0530 https://www.taxtmi.com/caselaws?id=128697