https://www.taxtmi.com/caselaws?id=153057 Promissory estoppel cannot restrain legislative power to amend or retrospectively validate a sales tax levy, even where an earlier exemption arose through subordinate notifications. A retrospective validating tax is not unconstitutional merely because taxpayers may be unable to pass on the burden. Constitutional invalidity requires a showing that the levy is confiscatory, extortionate, or imposes an unreasonable restriction on business or property rights. Limited retrospectivity, exemption for paper, and adjustment for tax borne on raw materials may reduce hardship and support the levy's validity. The constitutional challenge to the retrospective sales tax on exercise books therefore failed. en-us Mon, 14 Apr 1980 00:00:00 +0530 Tue, 16 Jul 2013 17:47:04 +0530 TaxTMI RSS Generator https://www.taxtmi.com/caselaws?id=153057 Promissory estoppel cannot restrain legislative power to amend or retrospectively validate a sales tax levy, even where an earlier exemption arose through subordinate notifications. A retrospective validating tax is not unconstitutional merely because taxpayers may be unable to pass on the burden. Constitutional invalidity requires a showing that the levy is confiscatory, extortionate, or imposes an unreasonable restriction on business or property rights. Limited retrospectivity, exemption for paper, and adjustment for tax borne on raw materials may reduce hardship and support the levy's validity. The constitutional challenge to the retrospective sales tax on exercise books therefore failed. Case-Laws VAT and Sales Tax Mon, 14 Apr 1980 00:00:00 +0530 https://www.taxtmi.com/caselaws?id=153057