https://www.taxtmi.com/caselaws?id=307876 A prospective amendment to the West Bengal Sales Tax Act's definition of "manufacture" could validly end the assessee's exemption for the unexpired period of its eligibility certificate from the date the amendment took effect. The earlier benefit was not withdrawn retrospectively; only future entitlement was affected. Exemption under a fiscal statute is a concession, not an irrevocable right, and promissory estoppel does not ordinarily prevent legislative alteration of a tax scheme. As the statutory scheme contained no express protection preserving the exemption after amendment, the assessee had no vested or accrued right to continue it. en-us Tue, 18 Mar 2008 00:00:00 +0530 Sat, 13 May 2023 11:53:48 +0530 TaxTMI RSS Generator https://www.taxtmi.com/caselaws?id=307876 A prospective amendment to the West Bengal Sales Tax Act's definition of "manufacture" could validly end the assessee's exemption for the unexpired period of its eligibility certificate from the date the amendment took effect. The earlier benefit was not withdrawn retrospectively; only future entitlement was affected. Exemption under a fiscal statute is a concession, not an irrevocable right, and promissory estoppel does not ordinarily prevent legislative alteration of a tax scheme. As the statutory scheme contained no express protection preserving the exemption after amendment, the assessee had no vested or accrued right to continue it. Case-Laws VAT and Sales Tax Tue, 18 Mar 2008 00:00:00 +0530 https://www.taxtmi.com/caselaws?id=307876